CN111954837A - Observation optics assembly based on extremely high refractive index eyepiece substrates - Google Patents

Abstract

A light-guiding substrate with an extremely high refractive index (n >2.2) allows the fabrication of a 70 ° field-of-view eyepiece with all three primary colors in a single eyepiece layer. Viewing optical assembly architectures utilizing such eyepieces to reduce size and cost, simplify manufacturing and assembly, and better accommodate novel microdisplay designs are disclosed herein.

Description

Observation optics assembly based on extremely high refractive index eyepiece substrates

claim of priority

This application claims priority to US Provisional Patent Application Serial No. 62/641,976, filed March 12, 2018, the entire contents of which are hereby incorporated by reference.

Applications incorporated by reference

This application incorporates by reference the entire contents of each of the following patent applications: Published October 4, 2018, Publication Serial No. 2018/0284585, entitled "LOW-PROFILE BEAM SPLITTER" (Attorney Docket No. MLEAP.111A) and US Patent Application Serial No. 62/474543, filed March 21, 2017, and Serial No. 62/570995, filed October 11, 2017 US Patent Application; Published Dec. 13, 2018, Publication Serial No. 2018/0356639, entitled "AUGMENTED REALITY DISPLAY HAVINGMULTI-ELEMENT ADAPTIVE LENS FOR CHANGING DEPTH PLANES (Augmentation of Multi-Element Adaptive Lenses with Altering Depth Planes) Reality Display)" (Attorney Docket No. MLEAP.119A) and US Patent Application Serial No. 62/518539 filed June 12, 2017 and Serial No. 62/536872, filed July 25, 2017 US Patent Application of ; US Patent Application Serial No. 15/796,669, filed October 27, 2017; US Patent Application Serial No. 16/215,477, filed on ___________, US Application Serial No. ___________, published on ___________, and US Patent Serial No. 62/597,359, filed on December 11, 2017 Application; US Patent Application Serial No. 62/624109, filed January 30, 2018; and US Patent Application Serial No. 16/262,659 published in ___________ US Application Serial No. ___________, and 2018 US Patent Application Serial No. 62/624,762, filed January 31, 2010. The contents of each of the above applications are hereby incorporated by reference.

technical field

The present application relates to observation optics assemblies, and more particularly, to observation optics assembly architectures configured to utilize extremely high refractive index light guide substrates. This viewing optics assembly can be used in optical systems, including augmented reality imaging and visualization systems.

Background technique

Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images, or parts thereof, are presented in a way that looks real or can be perceived as real to users. Virtual reality or "VR" scenarios typically involve presenting digital or virtual image information in a manner that is opaque to other actual real-world visual input; augmented reality or "AR" scenarios typically involve presenting digital or virtual image information as a representation of the real world around the user. Visualization enhancements. A mixed reality or "MR" scene is an AR scene and typically involves virtual objects that are integrated into, and respond to, the natural world. For example, an MR scene may include AR image content that appears to be occluded by, or otherwise perceived to interact with, objects in the real world.

Referring to Figure 1, an augmented reality scene 10 is shown. The user of the AR technology sees a real-world park-like setting 20 featuring people, trees, buildings in the background, and a concrete platform 30 . The user also perceives that he/she "sees" "virtual content" such as a robot statue 40 standing on a real-world platform 30, and a flying cartoon avatar character 50 that appears to be an avatar of a bumblebee, the elements 40, 50 are "virtual" because they don't exist in the real world. Due to the complexity of the human visual perception system, it is extremely challenging to develop AR technologies that facilitate the comfortable, natural-feeling, and rich presentation of virtual image elements from other virtual or real-world image elements.

The systems and methods disclosed herein address various challenges associated with AR and VR technologies.

SUMMARY OF THE INVENTION

A head mounted display system may be configured to project light onto a user's eyes to display augmented reality image content in the user's field of view. The head mounted display system may include a frame configured to be supported on a user's head. The head mounted display system may also include eyepieces disposed on the frame. At least a portion of the eyepiece may be transparent and/or positioned in front of the user's eyes when the user wears the head mounted display, such that the transparent portion transmits light from the environment in front of the user to the user's eyes to Provides a view of the environment in front of the user. The eyepiece may include one or more waveguides arranged to direct light into a user's eye to form augmented reality image content.

Various embodiments of head-mounted display systems include at least one projector having one or more pupils with outputs of multiple colors or wavelength ranges (eg, two or three colors) or wavelength range) of light (eg, image light) to produce images or image components of different colors, such as a red image component, a green image component, and a blue image component. These image components can be combined to provide nearly full color images. These color components can be imported into the user's eyes to display augmented reality or virtual image content. In some embodiments, the eyepiece in the head mounted display system includes a waveguide assembly including a plurality of waveguides stacked on top of each other.

In various embodiments of the display devices contemplated by the present application, one or more waveguides are included, the one or more waveguides comprising a material having an index of refraction greater than that of glass. For example, one or more of the waveguides in various embodiments of the display devices contemplated herein may include lithium niobate (LiNbO ₃ ) or silicon carbide (SiC). In various embodiments, one or more of the waveguides in the various embodiments of the display devices contemplated herein may include a material that is transparent to visible light and has an index of refraction greater than that of glass (eg, an index of refraction greater than or equal to about 1.79). One or more of a material comprising a relatively high index of refraction (eg, an index of refraction greater than that of glass and/or an index of refraction greater than or equal to about 1.79) compared to waveguides comprising glass and/or materials having an index of refraction less than about 1.79 The plurality of waveguides may advantageously expand the field of view of image content from the one or more projectors output to the user's eye through the one or more waveguides. Advantageously, in various embodiments of the display device, multiple colors or wavelengths of light (eg, red, green, and/or blue wavelengths of light) can be coupled simultaneously into components including a relatively high refractive index (eg, refractive index) and guide the light within a single waveguide of a material with an index of refraction greater than that of glass and/or a refractive index greater than or equal to about 1.79) and then cause the light to be output from the single waveguide at a similar angle for each color or wavelength A single waveguide couples out into the user's eye. Thus, instead of using three waveguides, such as one for each of the three colors (eg, red, green, and blue), a single waveguide can be employed to propagate three images from one or more projectors color components. This reduction in the number of waveguides may potentially have one or more advantages, such as reduced weight, overall eyepiece thickness, complexity, form factor, and/or increased light transmission and/or image quality.

In some embodiments, two color components of image content from one or more projectors may be coupled into and directed in a single waveguide, instead of three, and then coupled out to the user's eye. In some such designs, two waveguides can be used to accommodate the three colors. For example, a first waveguide can receive and guide two colors (eg, red and green, red and blue, or green and blue) in the first waveguide, and a second waveguide can receive, guide, and output a third Colors (eg, blue, green, and red, respectively). In some embodiments, a first waveguide can receive and direct two colors in the first waveguide (eg, red and green, red and blue, green and blue), and a second waveguide can receive, guide, and direct The viewer outputs a single third color or color component (eg, blue, green, and red, respectively). In other embodiments, the first waveguide may receive and guide two colors (eg, red and green) at the first waveguide, and the second waveguide may receive, guide, and out-couple the two colors or color components to the viewer, Wherein, one of the color components is different from the image color components (eg, green and blue) guided in the first waveguide. Using two waveguides instead of three (eg, one per depth or depth plane) can still reduce thickness, complexity and potentially provide one or more of the advantages discussed herein.

Likewise, different ones of the plurality of waveguides may include in-coupling optical elements configured to couple into a color or one of a plurality of wavelength ranges in light output from the pupil of the one or more projectors Light. In some embodiments, for example, a single in-coupling optical element in a waveguide is used to couple three colors or color components into the waveguide for guidance in the waveguide. In some embodiments, a single in-coupling optical element in a waveguide is used to couple two colors or color components into the waveguide for guidance in the waveguide. In other embodiments, different coupling optics are used to couple corresponding different colors or color components into a single waveguide for guidance within the single waveguide. For example, three in-coupling optical elements can be used to couple three respective colors or color components into a single waveguide. Similarly, two in-coupling optical elements can be used to couple two respective colors or color components into a single waveguide.

Thus, in one or more embodiments, two or more colors (eg, two or three colors) may be coupled using one or more in-coupling optical elements including a relatively high refractive index (eg, , within a single waveguide of a material with a refractive index greater than that of glass and/or a refractive index greater than or equal to about 1.79), so that the coupled two or more colors can be Propagation within a single waveguide of a material having an index of refraction (eg, an index of refraction greater than that of glass and/or an index of refraction greater than or equal to about 1.79) and coupled out to a viewer to render virtual image content. In some embodiments, a single coupled optical element may be configured to receive two or more colors of light containing image information from an imaging system (eg, a projection device) and to convert the received light containing image information Two or more colors of light are coupled into a single waveguide that includes a material having a relatively high index of refraction (eg, an index of refraction greater than that of glass and/or an index of refraction greater than or equal to about 1.79) such that the inclusion Light of two or more colors of image information propagates through the single waveguide by total internal reflection and couples out to the viewer to render virtual image content. In some embodiments, two or more coupled optical elements may be configured to receive two or more colors of light containing image information from an imaging system (eg, a projection device) and to convert the received Two or more colors of light containing image information are coupled into a single waveguide comprising a material with a relatively high index of refraction (eg, an index of refraction greater than that of glass and/or an index of refraction greater than or equal to about 1.79) , so that the two or more colors of light containing image information propagate through the single waveguide by total internal reflection and couple out to the viewer to render virtual image content. The one or more coupling optical elements may be aligned with one or more exit pupils of a projector or imaging system that emits light of the two or more colors containing image information.

The systems, methods and apparatus disclosed herein each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. Various example systems and methods are provided below.

Embodiment 1: a display system, comprising:

an image projection device configured to emit a multiplexed optical flow including a first optical flow of a first color, a second optical flow of a second color, and a third optical flow of a third color, the first color, the The second color and the third color are different, the first optical flow, the second optical flow and the third optical flow include image content; and

a waveguide comprising a material having an index of refraction greater than 1.79, the waveguide configured to receive the multiplexed optical flow emitted from the image projection device such that the first optical flow, the second optical flow and the The third optical flow is guided within the waveguide by multiple total internal reflections.

Embodiment 2: The display system of Embodiment 1, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.2.

Embodiment 3: The display system of any one of Embodiments 1-2, wherein the waveguide comprises a material with an index of refraction greater than or equal to 2.3.

Embodiment 4: The display system of any one of Embodiments 1-3, wherein the waveguide comprises lithium niobate.

Embodiment 5: The display system of any one of Embodiments 1-4, wherein the field of view of the waveguide is greater than about 30 degrees horizontally and greater than about 24 degrees vertically.

Embodiment 6: The display system of Embodiment 5, wherein the field of view of the waveguide is about 45 degrees in the horizontal direction and about 56 degrees in the vertical direction.

Embodiment 7: The display system of any one of Embodiments 1 to 6, further comprising at least one variable focus optical element configured to receive the multiplexed optical flow output from the waveguide such that all At least a portion of the multiplexed optical flow is directed to the user's eye, and the variable focus optical element is configured to vary the depth from which light from the waveguide appears to originate.

Embodiment 8: The display system of any one of Embodiments 1 to 6, wherein the multiplexed optical flow includes a first multiplexed optical flow, and the first multiplexed optical flow includes a associated image information.

Embodiment 9: The display system of Embodiment 8, wherein the waveguide includes a first waveguide associated with the first depth plane, wherein light emitted from the first waveguide is configured to The first multiplexed optical flow is directed to a viewer to produce an image that appears to originate from the first depth plane.

Embodiment 10: The display system of any one of Embodiments 8 to 9, wherein the image projection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane , the second multiplexed optical flow includes a plurality of optical flows having the first color, the second color and the third color, the first color, the second color and the third color Colors are different.

Embodiment 11: The display system according to Embodiment 10, further comprising:

a second waveguide associated with the second depth plane, the second waveguide comprising a material having an index of refraction greater than 1.79, the second waveguide configured to receive the second multiplexed transmitted from the image projection device optical flow such that the plurality of optical flows associated with the second multiplexed optical flow are directed through the second waveguide by multiple total internal reflections.

Embodiment 12: The display system of Embodiment 11, wherein the light emitted from the second waveguide is configured to direct the second multiplexed optical flow to a viewer to produce an appearance that appears to originate from the An image of the first depth plane.

Embodiment 13: The display system of any of Embodiments 11-12, wherein the second waveguide is included in an eyepiece of a head mounted display.

Embodiment 14: The display system of any of Embodiments 9-13, wherein the first waveguide is included in an eyepiece of a head mounted display.

Embodiment 15: The display system of any of Embodiments 1-7, wherein the waveguide is included in an eyepiece of a head mounted display.

Embodiment 16: The display system of any one of Embodiments 1 to 7 and 15, further comprising an in-coupling optical element configured to receive the multiplexed optical flow emitted from the image projection device, and Each of the first optical flow, the second optical flow, and the third optical flow are coupled into the waveguide to be guided within the waveguide by multiple total internal reflections.

Embodiment 17: The display system of any of Embodiments 1-16, wherein the image projection device comprises a light modulation device.

Embodiment 18: A display system, comprising:

an image projection device configured to emit a multiplexed optical flow including a first optical flow of a first color, a second optical flow of a second color, and a third optical flow of a third color, the first color, the The second color and the third color are different, the first optical flow, the second optical flow and the third optical flow include image content; and

a first waveguide and a second waveguide comprising a material having an index of refraction greater than 1.79,

wherein the first waveguide is configured to receive the first color and the second color, the second waveguide is configured to receive the third color, and a different color or combination of colors is coupled into the first color a waveguide and the second waveguide such that the first optical flow and the second optical flow are guided within the first waveguide by multiple total internal reflections and the third optical flow is excessive Subtotal internal reflection is guided within the second waveguide.

Embodiment 19: The display system of Embodiment 18, wherein the second waveguide is further configured to receive the first color such that the first optical flow is reflected in the first color through multiple total internal reflections. The second waveguide is guided inside.

Embodiment 20: The display system of Embodiment 18, wherein the second waveguide is further configured to receive the second color such that the second optical flow is reflected in the second optical flow through multiple total internal reflections. The second waveguide is guided inside.

Embodiment 21: The display system of Embodiment 18, wherein the second waveguide is configured not to couple into the first color or the second color such that the third optical flow passes through multiple times Internal reflections are mainly guided within the second waveguide.

Embodiment 22: The display system of any one of Embodiments 18-21, further comprising a first in-coupling optical element in the first waveguide, the first in-coupling optical element configured to Both the first optical flow and the second optical flow are coupled into the first waveguide, so that the first optical flow and the second optical flow are reflected in the first waveguide through multiple total internal reflections guided within.

Embodiment 23: The display system of any one of Embodiments 18-21, further comprising a first in-coupling optical element and a second in-coupling optical element in the first waveguide, the first in-coupling optical element The optical element and the second coupling optical element are configured to couple both the first optical flow and the second optical flow, respectively, into the first waveguide such that the first optical flow and the The second optical flow is guided within the first waveguide by multiple total internal reflections.

Embodiment 24: The display system of any one of Embodiments 18-21, further comprising a third in-coupling optical element in the second waveguide, the third in-coupling optical element configured to The third optical flow is coupled into the second waveguide such that the third optical flow is guided within the second waveguide by multiple total internal reflections.

Embodiment 25: The display system of Embodiment 24, wherein the third coupling optical element is further configured to couple the first optical flow or the second optical flow into the second waveguide , so that the first optical flow or the second optical flow is guided within the second waveguide by multiple total internal reflections.

Embodiment 26: The display system of Embodiment 24, further comprising a fourth in-coupling optical element configured to couple the first optical flow or the second optical flow in within the second waveguide such that the first optical flow or the second optical flow is guided within the second waveguide by multiple total internal reflections.

Embodiment 27: A method of manufacturing a diffractive optical element, the method comprising:

providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light;

disposing a patternable layer over the surface of the substrate;

patterning the patternable layer, the pattern including a plurality of features; and

The surface of the substrate is etched through the patternable layer to fabricate structures on the surface of the substrate, wherein the structures include diffractive features configured to diffract visible light.

Embodiment 28: The method of Embodiment 27, wherein the transparent material comprises LiNbO ₃ .

Embodiment 29: The method of Embodiment 27 or 28, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on the substrate on said surface.

Embodiment 30: The method of any one of Embodiments 27-29, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 31: The method of any of Embodiments 27-30, wherein the patternable layer comprises a resist or a polymer.

Embodiment 32: A method of manufacturing a diffractive optical element, the method comprising:

providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light;

disposing a patternable layer over the surface of the substrate; and

patterning the patternable layer, the pattern including a plurality of features,

wherein the plurality of features of the patterned patternable layer are configured to diffract visible light into the substrate to be directed in the substrate, or to be directed in the substrate Visible light diffracts out of the substrate.

Embodiment 33: The method of Embodiment 32, wherein the transparent material comprises LiNbO ₃ .

Embodiment 34: The method of Embodiment 32 or 33, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on the substrate on said surface.

Embodiment 35: The method of any of Embodiments 32-34, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 36: The method of any of Embodiments 32-35, wherein the patternable layer comprises a resist or a polymer.

Embodiment 37: A method of manufacturing a diffractive optical element, the method comprising:

providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light;

sputter-depositing a patternable layer over the surface of the substrate; and

The patternable layer is patterned, the pattern including a plurality of features.

Embodiment 38: The method of Embodiment 37, wherein the transparent material comprises LiNbO3.

Embodiment 39: The method of Embodiment 37 or 38, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 40: The method of any of Embodiments 37-39, wherein the patternable layer comprises a resist or a polymer.

Embodiment 41: A waveguide for propagating image content by total internal reflection, the waveguide comprising:

a substrate comprising a material with an index of refraction greater than 1.79 that is transparent to visible light, the substrate capable of propagating image content therein by total internal reflection;

a layer over the surface of the substrate, the layer comprising a material having a lower refractive index than the substrate, the layer comprising a pattern having a plurality of features,

wherein the plurality of features of the patterned patternable layer are configured to diffract visible light into the substrate to be directed therein, or to diffract visible light directed within the substrate out of the substrate the substrate.

Embodiment 42: The waveguide _of Embodiment 41, wherein the transparent material comprises LiNbO3.

Embodiment 43: The waveguide of Embodiment 41 or 42, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 44: The waveguide of any of Embodiments 41-43, wherein the patternable layer comprises a resist.

Embodiment 45: The waveguide of any of Embodiments 41-44, wherein the patternable layer comprises a polymer.

Embodiment 46: A head-mounted display device, comprising:

An eyepiece comprising at least one waveguide comprising a material having an index of refraction greater than 1.79, the waveguide comprising a first major surface, a second major surface opposite the first major surface, and a plurality of edges between the major surface and the second major surface; and

A plurality of diffractive features formed in at least one of the first major surface or the second major surface.

Embodiment 47: The head mounted display device of Embodiment 46, wherein the plurality of diffractive features are formed on the first major surface or the second major surface by etching at least one of the in at least one of the first major surface or the second major surface.

Embodiment 48: The head mounted display device of Embodiment 46 or 47, wherein the waveguide comprises a material having an index of refraction greater than 2.2.

Embodiment 49: The head mounted display device of any one of Embodiments 46-48, wherein the waveguide comprises lithium niobate.

Embodiment 50: The head mounted display device of any one of Embodiments 46-48, wherein the waveguide comprises silicon carbide.

Embodiment 51: The head mounted display device of any one of Embodiments 46 to 50, wherein at least some of the plurality of diffractive features are configured to couple into incident image light such that the coupled in Image light propagates through the waveguide by multiple total internal reflections at the first and second major surfaces.

Embodiment 52: The head mounted display device of any one of Embodiments 46 to 52, further comprising a variable focus lens between the waveguide and a viewer, wherein the variable focus lens is configured to change The focal plane of image light propagating through the waveguide by multiple total internal reflections at the first and second major surfaces and out-coupled towards the viewer. the waveguide. Embodiment 53: The head mounted display device of Embodiment 52, wherein the variable focus lens comprises a negative lens.

Embodiment 54: The head mounted display device of any one of Embodiments 52-53, wherein the variable focus lens comprises a liquid-filled lens.

Embodiment 55: The head mounted display device of any one of Embodiments 52-53, wherein the variable focus lens comprises liquid crystal.

Embodiment 56: The head mounted display device of any of Embodiments 52, 53, or 55, wherein the variable focus lens comprises a geometric phase lens.

Embodiment 57: The head mounted display device of any one of Embodiments 46 to 51, further comprising a negative lens between the waveguide and a viewer such that the negative lens receives a pass through at the first Multiple total internal reflections at one major surface and the second major surface cause light propagating through the waveguide and being coupled out of the waveguide toward the viewer.

Embodiment 58: The head mounted display device of Embodiment 57, wherein the negative lens comprises a static lens.

Embodiment 59: The head mounted display device of Embodiment 57 or 58, wherein the waveguide and the negative lens are included in a stacked waveguide assembly.

Embodiment 60: The head mounted display device of any one of Embodiments 57-59, further comprising an additional waveguide paired with an additional negative lens.

Embodiment 61: The head mounted display device of any one of Embodiments 57-60, further comprising a positive lens disposed between the waveguide and the real world.

Embodiment 62: The head mounted display device of any one of Embodiments 46-61, further comprising a polarizer stacked with the waveguide.

Embodiment 63: The head mounted display device of any one of Embodiments 46 to 62, wherein at least some of the plurality of diffractive features are configured to be coupled out towards the viewer by Image light propagating through the waveguide is caused by multiple total internal reflections at the first major surface and the second major surface.

Embodiment 64: The head mounted display device of any one of Embodiments 46 to 62, further comprising an imaging system configured to provide image light.

Embodiment 65: The head mounted display device of Embodiment 64, wherein the imaging system is outside the field of view of a viewer viewing the waveguide.

Embodiment 66: The head mounted display device of any one of Embodiments 64-65, wherein the imaging system comprises:

Lighting system;

a modulation element configured to receive unmodulated light from the lighting system; and

A projection optical system configured to transmit the image light output by the modulation element.

Embodiment 67: The head mounted display device of Embodiment 66, wherein the modulating element is reflective.

Embodiment 68: The head mounted display device of Embodiment 67, wherein unmodulated image light from the illumination system is transmitted through the projection optics toward the reflective modulation element, from the modulation The elements are reflected and transmitted back into the waveguide through the projection optics.

Embodiment 69: The head mounted display device of any one of Embodiments 66-68, wherein the lighting system comprises:

a light source configured to output visible light;

a light pipe configured to receive the visible light output from the light source; and

light redirecting elements,

wherein the light pipe is configured to transmit light output from the light source toward the light redirecting element by multiple total internal reflections; and

Wherein the light redirecting element is configured to redirect light propagating in the light pipe towards the modulating element.

Embodiment 70: The head mounted display device of Embodiment 69, wherein the light source includes a plurality of light emitting elements configured to emit light of a plurality of colors.

Embodiment 71: The head mounted display device of Embodiment 70, wherein the plurality of light emitting elements comprise light emitting diodes or lasers.

Embodiment 72: The head mounted display device of any one of Embodiments 70 to 71, further comprising an optical element configured to combine light emitted by the plurality of light emitting elements.

Embodiment 73: The head mounted display device of Embodiment 72, wherein the optical element is a dichroic beam combiner.

Embodiment 74: The head mounted display device of any one of Embodiments 69 to 73, wherein the light redirecting element is configured to be redirected through the waveguide towards the modulation element in the guide Light propagating in a light pipe.

Embodiment 75: The head mounted display device of any one of Embodiments 69 to 74, wherein the waveguide further comprises a light conditioning configured to tailor the distribution of light redirected by the light redirecting element optical instrument.

Embodiment 76: A head-mounted display device, comprising:

image projection equipment; and

An eyepiece including a waveguide comprising silicon carbide, the waveguide including a first major surface, a second major surface opposite the first major surface, and between the first major plane and the second major surface multiple edges of

Wherein the waveguide is configured to receive and direct light therein from the image projection device to direct an image into the eyes of a wearer of the head mounted display.

Embodiment 77: The head mounted display device of Embodiment 76, further comprising a plurality of diffractive features disposed on at least one of the first major surface or the second major surface.

Embodiment 78: The head mounted display device of Embodiment 77, wherein the plurality of diffractive features are formed on the first major surface or the second major surface by etching at least one of the in at least one of the first major surface or the second major surface.

Embodiment 79: The head mounted display device of any one of Embodiments 77-78, wherein at least some of the plurality of diffractive features are configured to couple into incident image light such that the coupled in Image light propagates through the waveguide by multiple total internal reflections at the first major plane and the second major surface.

Embodiment 80: The head mounted display device of any one of Embodiments 76 to 79, further comprising a variable focus lens between the waveguide and a viewer, wherein the variable focus lens is configured to change The focal plane of image light propagating through the waveguide by multiple total internal reflections at the first and second major surfaces and out-coupled towards the viewer. the waveguide.

Embodiment 81: The head mounted display device of Embodiment 80, wherein the variable focus lens comprises a negative lens.

Embodiment 82: The head mounted display device of any one of Embodiments 80-81, wherein the variable focus lens comprises a liquid-filled lens.

Embodiment 83: The head mounted display device of any one of Embodiments 80-81, wherein the variable focus lens comprises liquid crystal.

Embodiment 84: The head mounted display device of any of Embodiments 80, 81, or 83, wherein the variable focus lens comprises a geometric phase lens.

Embodiment 85: The head mounted display device of any one of Embodiments 76 to 79, further a negative lens located between the waveguide and a viewer, such that the negative lens Multiple total internal reflections at one major surface and the second major surface propagate through the waveguide and couple light out of the waveguide toward the viewer.

Embodiment 86: The head mounted display device of Embodiment 85, wherein the negative lens comprises a static lens.

Embodiment 87: The head mounted display device of Embodiment 85 or 86, wherein the waveguide and the negative lens are included in a stacked waveguide assembly.

Embodiment 88: The head mounted display device of any one of Embodiments 85 to 87, further comprising an additional waveguide paired with an additional negative lens.

Embodiment 89: The head mounted display device of any one of Embodiments 85 to 88, further comprising a positive lens disposed between the waveguide and the real world.

Embodiment 90: The head mounted display device of any one of Embodiments 76 to 89, further comprising a polarizer stacked with the waveguide.

Embodiment 91: The head mounted display device of any one of Embodiments 76 to 90, wherein at least some of the plurality of diffractive features are configured to be coupled out towards the viewer by Image light propagating through the waveguide is caused by multiple total internal reflections at the first major surface and the second major surface.

Embodiment 92: The head mounted display device of any one of Embodiments 76 to 91, further comprising an imaging system configured to provide image light.

Embodiment 93: The head mounted display device of Embodiment 92, wherein the imaging system is outside the field of view of a viewer viewing the waveguide.

Embodiment 94: The head mounted display device of any one of Embodiments 92 to 93, wherein the imaging system comprises:

Lighting system;

a modulation element configured to receive unmodulated light from the lighting system; and

A projection optical system configured to transmit the image light output by the modulation element.

Embodiment 95: The head mounted display device of Embodiment 94, wherein the modulating element is reflective.

Embodiment 96: The head mounted display device of Embodiment 95, wherein unmodulated image light from the illumination system is transmitted through the projection optical system toward the reflective modulation element from which is reflected and transmitted through the projection optics back into the waveguide.

Embodiment 97: The head-mounted display device of any one of Embodiments 94-96, wherein the lighting system comprises:

a light source configured to output visible light;

a light pipe configured to receive the visible light output from the light source; and

light redirecting elements,

wherein the light pipe is configured to transmit light output from the light source toward the light redirecting element by multiple total internal reflections; and

Wherein the light redirecting element is configured to redirect light propagating in the light pipe towards the modulating element.

Embodiment 98: The head mounted display device of Embodiment 98, wherein the light source includes a plurality of light emitting elements configured to emit light of a plurality of colors.

Embodiment 99: The head mounted display device of Embodiment 98, wherein the plurality of light emitting elements comprise light emitting diodes or lasers.

Embodiment 100: The head mounted display device of any one of Embodiments 98-99, further comprising an optical element configured to combine light emitted by the plurality of light emitting elements.

Embodiment 101: The head mounted display device of Embodiment 100, wherein the optical element is a dichroic beam combiner.

Embodiment 102: The head mounted display device of any one of Embodiments 98 to 101, wherein the light redirecting element is configured to be redirected through the waveguide towards the modulation element at the guide Light propagating in a light pipe.

Embodiment 103: The head mounted display device of any one of Embodiments 98 to 102, wherein the waveguide further comprises a light conditioning configured to tailor the distribution of light redirected by the light redirecting element optical instrument.

Embodiment 104: A display system, comprising:

An image injection device configured to emit a multiplexed optical flow, the multiplexed optical flow including: a first optical flow including image content associated with a first color; a second optical flow including a second optical flow associated image content; and a third optical flow including image content associated with the third color;

a waveguide comprising a material having an index of refraction greater than 1.79; and

a first coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and couple into the multiplexed optical flow such that the first optical flow, the second optical flow The flow and the third optical flow propagate through the waveguide by multiple total internal reflections.

Embodiment 105: The display system of Embodiment 104, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.2.

Embodiment 106: The display system of any of Embodiments 104-105, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.3.

Embodiment 107: The display system of any of Embodiments 104-106, wherein the waveguide comprises lithium niobate or silicon carbide.

Embodiment 108: The display system of any one of Embodiments 104-107, wherein the waveguide has a field of view greater than about 30 degrees horizontally and greater than about 24.7 degrees vertically.

Embodiment 109: The display system of Embodiment 108, wherein the field of view of the waveguide is approximately 45.9 degrees in the horizontal direction and approximately 56.1 degrees in the vertical direction.

Embodiment 110: The display system of any of Embodiments 104-109, wherein the multiplexed optical flow includes image information associated with a first depth plane.

Embodiment 111: The display system of Embodiment 110, wherein the waveguide is associated with the first depth plane, and wherein the light emitted from the waveguide is configured to produce light that appears to originate from the first depth plane. An image of a depth plane.

Embodiment 112: The display system of any one of Embodiments 110 to 111, wherein the image injection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane , the second multiplexed optical flow includes a plurality of optical flows associated with the first color, the second color and the third color.

Embodiment 113: The display system of Embodiment 112, further comprising:

a second waveguide associated with the second depth plane, the second waveguide comprising a material having an index of refraction greater than 1.79; and

A second in-coupling optical element configured to receive the second multiplexed optical stream emitted from the image injection device and configured to couple into the second multiplexed optical stream such that the plurality of The optical flow propagates through the second waveguide by multiple total internal reflections.

Embodiment 114: The display system of Embodiment 113, wherein the light emitted from the second waveguide is configured to produce an image that appears to originate from the second depth plane.

Embodiment 115: The display system of any of Embodiments 114-115, wherein the second waveguide is included in an eyepiece of a head mounted display.

Embodiment 116: The display system of any of Embodiments 104-115, wherein the waveguide is included in an eyepiece of a head mounted display.

Embodiment 117: The display system of any of Embodiments 115-116, wherein the head mounted display comprises glasses.

Embodiment 118: The display system of any of Embodiments 104-117, wherein the image injection device comprises a light modulation device.

Embodiment 119: A display system, comprising:

An image injection device configured to emit a multiplexed optical flow, the multiplexed optical flow including: a first optical flow including image content associated with a first color; a second optical flow including a second optical flow associated image content; and a third optical flow including image content associated with the third color;

a waveguide comprising a material having an index of refraction greater than 1.79; and

A first plurality of coupled-in optical elements configured to receive the multiplexed optical flow emitted from the image injection device and to couple into the multiplexed optical flow such that the first optical flow, the second optical flow The second optical flux and the third optical flux propagate through the waveguide by multiple total internal reflections.

Embodiment 120: The display system of Embodiment 119, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.2.

Embodiment 121: The display system of any one of Embodiments 119-120, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.3.

Embodiment 122: The display system of any of Embodiments 119-121, wherein the waveguide comprises lithium niobate or silicon carbide.

Embodiment 123: The display system of any one of Embodiments 119-122, wherein the waveguide has a field of view greater than about 30 degrees horizontally and greater than about 24.7 degrees vertically.

Embodiment 124: The display system of Embodiment 123, wherein the field of view of the waveguide is approximately 45.9 degrees in the horizontal direction and approximately 56.1 degrees in the vertical direction.

Embodiment 125: The display system of any of Embodiments 119-124, wherein the first plurality of in-coupling optical elements comprises:

a first in-coupling optical element configured to be coupled into the first optical flow;

a second in-coupling optical element configured to couple into the second optical flow; and

A third in-coupling optical element configured to couple in the third optical flow.

Embodiment 126: The display system of any of Embodiments 119-125, wherein the multiplexed optical flow includes image information associated with a first depth plane.

Embodiment 127: The display system of Embodiment 126, wherein the waveguide is associated with the first depth plane, and wherein the light emitted from the waveguide is configured to produce light that appears to originate from the first depth plane. An image of a depth plane.

Embodiment 128: The display system of any one of Embodiments 125 to 127, wherein the image injection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane , the second multiplexed optical flow includes a plurality of optical flows associated with the first color, the second color and the third color.

Embodiment 129: The display system of Embodiment 128, further comprising:

a second waveguide associated with the second depth plane, the second waveguide comprising a material having an index of refraction greater than 1.79; and

A second plurality of coupled optical elements configured to receive the second multiplexed optical flow emitted from the image injection device and configured to couple into the second multiplexed optical flow such that the A plurality of optical fluxes propagate through the second waveguide through multiple total internal reflections.

Embodiment 130: The display system of Embodiment 129, wherein the light emitted from the second waveguide is configured to produce an image that appears to originate from the second depth plane.

Embodiment 131: The display system of any of Embodiments 129-130, wherein the second waveguide is included in an eyepiece of a head mounted display.

Embodiment 132: The display system of any of Embodiments 119-131, wherein the waveguide is included in an eyepiece of a head mounted display.

Embodiment 133: The display system of any of Embodiments 131-132, wherein the head mounted display comprises glasses.

Embodiment 134: The display system of any of Embodiments 119-133, wherein the image injection device comprises a light modulation device.

Embodiment 135: A display system comprising:

An image injection device configured to emit a multiplexed optical flow, the multiplexed optical flow including: a first optical flow including image content associated with a first color; a second optical flow including a second optical flow associated image content; and a third optical flow including image content associated with the third color;

a first waveguide comprising a material having an index of refraction greater than 1.79;

a second waveguide comprising a material having an index of refraction greater than 1.79;

a first coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the first optical flow and the second optical flow into the first waveguide inside such that the first optical flow and the second optical flow propagate through the first waveguide by multiple total internal reflections; and

A second in-coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the third optical flow into the second waveguide such that the first optical flow The three optical fluxes propagate through the second waveguide through multiple total internal reflections.

Embodiment 136: The display system of Embodiment 135, wherein the second coupling optical element is further configured to couple the first optical flow or the second optical flow into the second waveguide , so that the first optical flow or the second optical flow propagates through the first waveguide through multiple total internal reflections.

Embodiment 137: The display system of any one of Embodiments 135-136, wherein at least one of the first waveguide and the second waveguide comprises a material having an index of refraction greater than or equal to 2.2.

Embodiment 138: The display system of any one of Embodiments 135-137, wherein at least one of the first waveguide and the second waveguide comprises a material having an index of refraction greater than or equal to 2.3.

Embodiment 139: The display system of any one of Embodiments 135-137, wherein at least one of the first waveguide and the second waveguide comprises lithium niobate or silicon carbide.

Embodiment 140: The display system of any one of Embodiments 135-139, wherein the field of view of at least one of the first waveguide and the second waveguide is greater than about 30 in the horizontal direction degrees, greater than about 24.7 degrees in the vertical direction.

Embodiment 141: The display system of Embodiment 140, wherein a field of view of at least one of the first waveguide and the second waveguide is approximately 45.9 degrees in the horizontal direction and about 45.9 degrees in the vertical direction is about 56.1 degrees.

Embodiment 142: The display system of any one of Embodiments 135-141, wherein the multiplexed optical flow includes image information associated with a first depth plane.

Embodiment 143: The display system of Embodiment 142, wherein the first waveguide and the second waveguide are associated with the first depth plane, and wherein the The light emitted by the two waveguides is configured to produce an image that appears to originate from the first depth plane.

Embodiment 144: The display system of any one of Embodiments 135 to 143, wherein the image injection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane , the second multiplexed optical flow includes a plurality of optical flows associated with the first color, the second color and the third color.

Embodiment 145: The display system of Embodiment 144, further comprising:

two waveguides associated with the second depth plane, the two waveguides comprising a material having an index of refraction greater than 1.79;

A third in-coupling optical element configured to receive the second multiplexed optical flow emitted from the image injection device and configured to associate light with the first color and the second color flow is coupled into a first of the two waveguides such that the optical flow associated with the first color and the second color propagates through the two waveguides by multiple total internal reflections the first waveguide; and

a fourth coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the optical flow associated with the third color into the two waveguides within a second waveguide of the two waveguides such that the optical flow associated with the third color propagates through the second waveguide of the two waveguides by multiple total internal reflections.

Embodiment 146: The display system of Embodiment 145, wherein the fourth coupling optical element is further configured to couple an optical flow associated with the first color or the second color into the within a second of the two waveguides such that the optical flux associated with the first color or the second color propagates through the second of the two waveguides by multiple total internal reflections waveguide.

Embodiment 147: The display system of any of Embodiments 145-146, wherein the light emitted from the two waveguides is configured to produce an image that appears to originate from the second depth plane.

Embodiment 148: The display system of any of Embodiments 145-147, wherein the two waveguides associated with the second depth plane are included in an eyepiece of a head mounted display.

Embodiment 149: The display system of any one of Embodiments 135-148, wherein the first waveguide and the second waveguide are included in an eyepiece of a head mounted display.

Embodiment 150: The display system of any of Embodiments 148-149, wherein the head mounted display comprises glasses.

Embodiment 151: The display system of any of Embodiments 135-150, wherein the image injection device comprises a light modulation device.

Embodiment 152: A display system comprising:

An image injection device configured to emit a multiplexed optical flow, the multiplexed optical flow including: a first optical flow including image content associated with a first color; a second optical flow including a second optical flow associated image content; and a third optical flow including image content associated with the third color;

a first waveguide comprising a material having an index of refraction greater than 1.79;

a second waveguide comprising a material having an index of refraction greater than 1.79;

a first coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the first optical flow into the first waveguide such that the first optical flow An optical flux propagates through the first waveguide by multiple total internal reflections; and

A second in-coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the second optical flow into the first waveguide such that the first optical flow Two optical fluxes propagate through the first waveguide through multiple total internal reflections; and

A third in-coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the third optical flow into the second waveguide such that the first optical flow Three optical streams propagate through the second waveguide by multiple total internal reflections.

Embodiment 153: The display system of Embodiment 152, wherein the third coupling optical element is further configured to couple the first optical flow or the second optical flow into the second waveguide , so that the first optical flow or the second optical flow light propagates through the first waveguide through multiple total internal reflections.

Embodiment 154: The display system of Embodiment 152, further comprising a fourth coupling optical element configured to couple the first optical flow or the second optical flow into the second waveguide, such that the first optical flow or the second optical flow propagates through the first waveguide through multiple total internal reflections.

Embodiment 155: The display system of any one of Embodiments 152-154, wherein at least one of the first waveguide and the second waveguide comprises a material having an index of refraction greater than or equal to 2.2.

Embodiment 156: The display system of any one of Embodiments 152-155, wherein at least one of the first waveguide and the second waveguide comprises a material having an index of refraction greater than or equal to 2.3.

Embodiment 157: The display system of any one of Embodiments 152-156, wherein at least one of the first waveguide and the second waveguide comprises lithium niobate or silicon carbide.

Embodiment 158: The display system of any one of Embodiments 152 to 157, wherein the field of view of at least one of the first waveguide and the second waveguide is greater than about 30 degrees horizontally, Greater than about 24.7 degrees in the vertical direction.

Embodiment 159: The display system of Embodiment 158, wherein the field of view of at least one of the first waveguide and the second waveguide is about 45.9 degrees in the horizontal direction, The vertical direction is about 56.1 degrees.

Embodiment 160: The display system of any one of Embodiments 152-159, wherein the multiplexed optical flow includes image information associated with a first depth plane.

Embodiment 161: The display system of Embodiment 160, wherein the first waveguide and the second waveguide are associated with the first depth plane, and wherein the first waveguide and the second waveguide are The light emitted by the two waveguides is configured to produce an image that appears to originate from the first depth plane.

Embodiment 162: The display system of any one of Embodiments 152 to 161, wherein the image injection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane , the second multiplexed optical flow includes a plurality of optical flows associated with the first color, the second color and the third color.

Embodiment 163: The display system of Embodiment 162, further comprising:

two waveguides associated with the second depth plane, the two waveguides comprising a material having an index of refraction greater than 1.79;

a fifth in-coupling optical element configured to receive the second multiplexed optical flow emitted from the image injection device and configured to associate light with the first color and the second color flow is coupled into a first of the two waveguides such that the optical flow associated with the first color and the second color propagates through the two waveguides by multiple total internal reflections the first waveguide; and

a sixth in-coupling optical element configured to receive the multiplexed optical flow emitted from the image injection device and configured to couple the optical flow associated with the third color into the two waveguides within a second waveguide of the two waveguides such that the optical flow associated with the third color propagates through the second waveguide of the two waveguides by multiple total internal reflections.

Embodiment 164: The display system of Embodiment 163, wherein the sixth coupling optical element is further configured to couple light associated with the first color or the second color into the two within a second of the waveguides such that the optical flow associated with the first color or the second color propagates through the second of the two waveguides by multiple total internal reflections .

Embodiment 165: The display system of any one of Embodiments 163 to 165, wherein the light emitted from the two waveguides is configured to produce an image that appears to originate from the second depth plane.

Embodiment 166: The display system of any one of Embodiments 163 to 165, wherein the two waveguides associated with the second depth plane are included in an eyepiece of a head mounted display.

Embodiment 167: The display system of any of Embodiments 152-166, wherein the first waveguide and the second waveguide are included in an eyepiece of a head mounted display.

Embodiment 168: The display system of any one of Embodiments 166-167, wherein the head mounted display comprises glasses.

Embodiment 169: The display system of any of Embodiments 152-168, wherein the image injection device comprises a light modulation device.

Embodiment 170: A method of making a diffractive optical element, the method comprising:

providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light;

disposing a patternable layer over the surface of the substrate;

patterning the patternable layer, the pattern including a plurality of features; and

The surface of the substrate is etched through the patternable layer to fabricate structures on the surface of the substrate, wherein the structures include diffractive features configured to diffract visible light.

Embodiment 171 : The method of Embodiment 170, wherein the transparent material comprises LiNbO ₃ or silicon carbide.

Embodiment 172: The method of Embodiment 170, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on all of the substrate. above the surface.

Embodiment 173: The method of Embodiment 170, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 174: The method of Embodiment 170, wherein the patternable layer comprises a resist or a polymer.

Embodiment 175: A method of making a diffractive optical element, the method comprising:

providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light;

disposing a patternable layer over the surface of the substrate; and

patterning the patternable layer, the pattern including a plurality of features,

wherein the plurality of features of the patterned patternable layer are configured to diffract visible light.

Embodiment 176: The method of Embodiment 175, wherein the transparent material comprises LiNbO ₃ or silicon carbide.

Embodiment 177: The method of Embodiment 175, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on all of the substrate. above the surface.

Embodiment 178: The method of Embodiment 175, wherein the surface of the substrate is discharged prior to disposing the patternable layer.

Embodiment 179: The method of Embodiment 175, wherein the patternable layer comprises a resist or a polymer.

Embodiment 180: The display system of any one of Embodiments 1-26, wherein the waveguide material comprises silicon carbide.

Embodiment 181: The method of any of Embodiments 27-40, wherein the transparent material comprises silicon carbide.

Embodiment 182: The waveguide of any of Embodiments 41-45, wherein the transparent material comprises silicon carbide.

Embodiment 183: A head-mounted display device, comprising:

image projection equipment; and

An eyepiece comprising a waveguide comprising a material having an index of refraction greater than 1.79, the waveguide comprising a first major surface, a second major surface opposite the first major surface, and a connection between the first major surface and the a plurality of edges between the second major surfaces,

Wherein the waveguide is configured to receive and direct light therein from the image projection device to direct an image into the eyes of a wearer of the head mounted display.

Embodiment 184: The head mounted display device of Embodiment 183, wherein the waveguide material has an index of refraction greater than or equal to 2.2.

Embodiment 185: The head mounted display device of any one of Embodiments 183 to 184, wherein the waveguide material has an index of refraction greater than or equal to 2.3.

Embodiment 186: The head mounted display device of any one of Embodiments 183 to 185, wherein the material comprises lithium niobate.

Embodiment 187: The head mounted display device of any one of Embodiments 183 to 185, wherein the material comprises silicon carbide.

Embodiment 188: The head mounted display device of any one of Embodiments 183 to 187, wherein the waveguide has a field of view greater than about 30 degrees horizontally and greater than about 24 degrees vertically.

Embodiment 189: The head mounted display device of Embodiment 188, wherein the field of view of the waveguide is about 45 degrees in the horizontal direction and about 56 degrees in the vertical direction.

Embodiment 190: The head mounted display device of any one of Embodiments 183 to 189, further comprising a plurality of disposed on at least one of the first major surface or the second major surface Diffraction features.

Embodiment 191: The head mounted display device of Embodiment 190, wherein the plurality of diffractive features are formed on the first major surface or the second major surface by etching at least one of the in at least one of the first major surface or the second major surface.

Embodiment 192: The head mounted display device of any one of Embodiments 183 to 191, wherein at least some of the plurality of diffractive features are configured to couple into incident image light such that the coupled in Image light propagates through the waveguide by multiple total internal reflections at the first and second major surfaces.

Embodiment 193: The head mounted display device of any one of Embodiments 183 to 192, further comprising a variable focus lens between the waveguide and a viewer, wherein the variable focus lens is configured to change a focal plane of image light propagating through the waveguide by multiple total internal reflections at the first and second major surfaces and being coupled out of the waveguide towards the viewer waveguide.

Embodiment 194: The head mounted display device of Embodiment 193, wherein the variable focus lens comprises a negative lens.

Embodiment 195: The head mounted display device of any one of Embodiments 193 to 194, wherein the variable focus lens comprises a liquid-filled lens.

Embodiment 196: The head mounted display device of any one of Embodiments 193 to 195, wherein the variable focus lens comprises liquid crystal.

Embodiment 197: The head mounted display device of any of Embodiments 193, 194, or 196, wherein the variable focus lens comprises a geometric phase lens.

Embodiment 198: The head mounted display device of any one of Embodiments 183 to 192, further comprising a negative lens between the waveguide and a viewer, such that the negative lens receives a pass through at the first Light propagating through the waveguide and being coupled out of the waveguide toward the viewer by multiple total internal reflections at a major plane and the second major surface.

Embodiment 199: The head mounted display device of Embodiment 198, wherein the negative lens comprises a static lens.

Embodiment 200: The head mounted display device of Embodiment 198 or 199, wherein the waveguide and the negative lens are included in a stacked waveguide assembly.

Embodiment 201: The head mounted display device of any one of Embodiments 198 to 200, further comprising an additional waveguide paired with an additional negative lens.

Embodiment 202: The head mounted display device of any one of Embodiments 198 to 201, further comprising a positive lens disposed between the waveguide and the real world.

Embodiment 203: The head mounted display device of any one of Embodiments 183 to 202, further comprising a polarizer stacked with the waveguide.

Embodiment 204: The head mounted display device of any one of Embodiments 183 to 203, wherein at least some of the plurality of diffractive features are configured to be coupled out towards the viewer by Image light propagating through the waveguide is caused by multiple total internal reflections at the first major plane and the second major surface.

Embodiment 205: The head mounted display device of any one of Embodiments 183 to 204, further comprising an imaging system configured to provide image light.

Embodiment 206: The head mounted display device of Embodiment 205, wherein the imaging system is outside the field of view of a viewer viewing the waveguide.

Embodiment 207: The head mounted display device of any one of Embodiments 205 to 206, wherein the imaging system comprises:

Lighting system;

a modulation element configured to receive unmodulated light from the lighting system; and

A projection optical system configured to transmit the image light output by the modulation element.

Embodiment 208: The head mounted display device of Embodiment 207, wherein the modulating element is reflective.

Embodiment 209: The head mounted display device of Embodiment 208, wherein unmodulated image light from the illumination system is transmitted through the projection optics toward the reflective modulation element, from the modulation The elements are reflected and transmitted back into the waveguide through the projection optics.

Embodiment 210: The head mounted display device of any one of Embodiments 207 to 209, wherein the lighting system comprises:

a light source configured to output visible light;

a light pipe configured to receive the visible light output from the light source; and

light redirecting elements,

wherein the light pipe is configured to transmit light output from the light source toward the light redirecting element by multiple total internal reflections; and

Wherein the light redirecting element is configured to redirect light propagating in the light pipe towards the modulating element.

Embodiment 211: The head mounted display device of Embodiment 210, wherein the light source includes a plurality of light emitting elements configured to emit light of a plurality of colors.

Embodiment 212: The head mounted display device of Embodiment 211, wherein the plurality of light emitting elements comprise light emitting diodes or lasers.

Embodiment 213: The head mounted display device of any one of Embodiments 211 to 212, further comprising an optical element configured to combine light emitted by the plurality of light emitting elements.

Embodiment 214: The head mounted display device of Embodiment 213, wherein the optical element is a dichroic beam combiner.

Embodiment 215: The head mounted display device of any one of Embodiments 210 to 214, wherein the light redirecting element is configured to be redirected through the waveguide towards the modulation element in the guide Light propagating in a light pipe.

Embodiment 216: The head mounted display device of any one of Embodiments 210 to 215, wherein the waveguide further comprises a light conditioning configured to tailor the distribution of light redirected by the light redirecting element optical instrument.

Embodiment 217: The head mounted display device of any one of Embodiments 183 to 216, further comprising a diffraction grating in or on the waveguide.

Description of drawings

1 illustrates a view of augmented reality (AR) seen by a user through an AR device, according to some embodiments.

FIG. 2 shows an example of a wearable display system in accordance with some embodiments.

3 illustrates a display system for simulating three-dimensional imagery for a user, according to some embodiments.

4 illustrates aspects of a method of simulating a three-dimensional imagery using multiple depth planes, according to some embodiments.

5A-5C illustrate the relationship between the radius of curvature and the focal radius in accordance with some embodiments.

6 illustrates an example of a waveguide stack for outputting image information to a user, according to some embodiments.

Figure 7 shows an example of an exit beam output by a waveguide in accordance with some embodiments.

8 shows an example of a stacked waveguide assembly in which each depth plane includes an image formed using multiple different component colors, according to some embodiments.

9A illustrates a cross-sectional side view of an example of a stack of waveguides, each stacked waveguide including an in-coupling optical element, in accordance with some embodiments.

9B illustrates a perspective view of an example of the stacked waveguide set of FIG. 9A in accordance with some embodiments.

9C illustrates a top plan view of an example of the stacked waveguide set of FIGS. 9A and 9B in accordance with some embodiments.

FIG. 10 shows an example of a display system including an imaging system, a waveguide including a high index of refraction material, and a plurality of variable focus elements, and including, for example, a liquid-filled lens configured to provide an A depth plane or an image with the same depth.

Figure 11 shows an example of a display system including an imaging system, a waveguide including a high index of refraction material, and a plurality of variable focus elements, and including, for example, a geometric phase (GP) lens configured to provide From multiple depth planes or images of the same depth.

FIG. 12 shows an example of a display system including an imaging system and two waveguides including a high refractive index material included in a waveguide assembly configured to provide at least one focal plane or depth middle.

Figure 13 shows an imaging system into which unmodulated illumination light is input through a projection optical system towards a reflective modulation element such that modulated light comprising image information is reflected from the modulation element and through the projection optics towards a reflective modulation element The waveguide stack is transmitted back.

Figure 14A shows a display system with constrained working distances for configuring a first and second set of waveguides for two depth planes, each set of waveguides including three waveguides. Figure 14B shows a display system similar to that shown in Figure 14A additionally including lenses included in the first and second waveguide groups. 14C illustrates a display system with improved working distance for configuring waveguides, according to some embodiments.

14D-1, 14D-2, 14D-3, 14E-1, 14E-2, and 14E-3 illustrate various design considerations for configuring the working distance of a display system, according to some embodiments.

Figure 15 shows an example of a display system including an imaging system and three waveguides comprising high refractive index material configured to provide three focal planes or depths.

FIG. 16 shows an embodiment of a display system including a lighting tube 1630.

17A and 17B illustrate side and top views including various illumination tubes configured to provide various colored illuminations to embodiments of the imaging system.

Figures 18A and 18B show flow diagrams of two different methods of fabricating diffraction gratings on the surface of a substrate (eg, a waveguide) comprising a high refractive index material.

The drawings are provided to illustrate example embodiments and are not intended to limit the scope of the present disclosure. The same reference numerals refer to the same parts throughout.

Detailed ways

VR and AR experiences may be provided by display systems having displays in which images corresponding to multiple depth planes are provided to the viewer. The image may be relayed through an exit pupil of the projector, which is associated with specific display optics, such as a waveguide, configured to display images from a specific depth plane. Thus, the display system facilitates providing depth cues to the user based on accommodation of the eye, or similarly providing accommodation cues to the user based on the depth of an image or virtual content. The accommodation of the eye can bring into focus different content located at different depth planes in the scene. As discussed herein, such depth cues help the viewer to provide reliable depth perception.

In some configurations, panchromatic images may be formed for various depth planes by overlaying component images each having a particular component color. For example, red, green, and blue images may be output separately to form individual full-color images. Thus, each depth plane may have multiple component color images associated with it. As disclosed herein, a component color image can be output using a waveguide that couples in light containing image information, distributes the in-coupled light across the waveguide, and then couples the light out toward a viewer. In-coupling optical elements such as diffractive elements (eg, diffraction gratings) may be used to couple light into the waveguide, and out-coupling optical elements (which may also be diffractive elements such as gratings) are used to couple light out of the waveguide.

In many cases, display systems that provide VR and AR experiences (e.g. mixed or augmented reality (AR), near-eye displays) are required to be lightweight, low cost, small form factor, wide field of view for virtual images, and at least a Be as transparent as possible. Additionally, in various embodiments, configurations that present virtual image information in multiple focal planes (eg, two or more) are required in order to not exceed acceptable vergence-accommodation mismatch tolerances Practical for a variety of applications. Multiple focal planes may also be referred to herein as multiple depth planes or depths (eg, from which image content appears to originate). Many architectures exist that can achieve some of these goals, but few can fully achieve all of them. To achieve many of the goals identified above, it is necessary to find an architecture that integrates small, even the smallest possible imaging systems, such as microdisplays (eg projectors) that include the required number of pixels for a given field of view. It may also be desirable to deliver a desired number of focal planes (or depth planes) or depth with fewer, reduced, or minimal number of eyepiece layers. Additionally, efficient, transparent and/or low-cost focusing elements responsible for imaging the designed focal plane or depth plane at the desired location, as well as lightweight, high optical quality to achieve the desired field of view and small form factor may be required compact eyepiece design.

An architectural class of several combinations of viewing optics that can be used to generate mixed reality light fields that contain static optics on both sides of the infinity focusing eyepiece to provide the viewer with a location that is not far from infinity An unpowered view of the real world combined with virtual images at (eg depth). This can be achieved by using a positive/negative lens combination in which both lenses have the same optical power.

A set of compact eyepiece solutions incorporate light guides carrying leaky gratings (such as exit pupil expander ("EPE")/orthogonal pupil expander ("OPE") configurations) redirected from the imaging system and One input pupil is duplicated to produce a wide field of view with a large pupil, facilitating comfortable, flexible multi-IPD (interpupillary distance) viewing and eye movement. In this application, the terms light guide and waveguide are used interchangeably. In various embodiments, the light guide may include nanostructured or microstructured gratings. In some embodiments, the eyepiece includes a grating or diffractive optical element that forms an EPE/OPE combination on both sides of the light guide (eg, major surface, front surface, rear surface, etc.). In some embodiments, the grating or diffractive optical element includes a combined pupil expander (pupil expander that both expands and couples out light) formed on a single surface of the light guide.

A compact imaging system for generating an image, such as a microdisplay, may include a spatial light modulator, an optical system (eg, projection optics) that projects the image formed by the spatial light modulator, and a device that illuminates the spatial light modulator to generate the image. lighting module. Other microdisplay technologies, such as multi-core or single-core optical fibers, or micro-LED displays, can also be used as light sources or image sources. It may be desirable for the lighting module to be compact and to transfer reduced or minimal heat to the optical elements of the microdisplay.

An optical system (eg, projection optics) can be configured to generate the output pupil of the microdisplay. Without loss of generality, the output pupil may correspond to the pupil of the optical system through which light exits from the optical system. Light exiting the output pupil of the microdisplay can be made to intersect or approximate the coupling element (eg, a grating) on the light guide of the eyepiece. Many microdisplay solutions can be configured to generate separate sub-pupils for different colors of image light emitted from the imaging systems that have been described and illustrated. For example, one embodiment of an imaging system has a first set of three separate output sub-pupils to output light corresponding to red, green, and blue image components for a first depth or focal plane, and a second set of three Separate output sub-pupils to output light corresponding to the red, green and blue image components for a second depth or focal plane. In some embodiments, for each depth plane, three input sub-pupils may be included in the eyepiece to receive red, green, and blue light from one or more light sources. However, such systems may be bulky and may not be practical for achieving the goals of small architectural form factor and reduced volume/weight.

One or more of the waveguides in the eyepiece may include a light guide material of a specific index of refraction suitable to host the desired range of field angles for the system's field of view. For example, since a single eyepiece layer cannot achieve all the raster vectors and field angles required to display all three colors superimposed on each other, separate eyepiece layers are preferably used for each of the red, green and blue image components. However, the fabrication cost of the waveguide stacks for the eyepieces of head-mounted VR and/or AR devices increases as the number of waveguides in the waveguide stack increases. The fabrication cost of the waveguide stack for the eyepiece of the head-mounted VR and/or AR device may also depend on the handedness (eg, "left" or "right") of the waveguide stack. For example, the manufacturing cost of manufacturing different waveguide stacks configured to be in front of the right and left eyes is higher than the manufacturing cost of manufacturing a single waveguide stack that can be located in front of the left eye and a single waveguide stack that can be located in front of the right eye. As described above, various embodiments of the waveguide stack for the eyepiece of the head-mounted VR and/or AR device may include 6 separate designs and 6 separate waveguides. The cost of manufacturing and assembling such a waveguide stack can be further increased due to the increased cost of monitoring the quality of the individual waveguides in the waveguide stack during the manufacturing and assembly process. Since a waveguide stack comprising more waveguides is likely to be rejected if the quality of the individual waveguides in the waveguide stack is not up to standard, it may further increase the cost of manufacturing and assembling such a waveguide stack. Furthermore, there is an increased likelihood of optical quality degradation, as each color component is required to produce its image co-incident with the other color components in x, y, and z. Additionally, variations in the total thickness of the waveguide stack comprising 6 waveguides can independently change the pixel position of each color component and may cause some color pixels to be out of focus. Computationally expensive calibration/image warping can be implemented to correct for color component variations caused by thickness variations. For these reasons, waveguide stacks with fewer waveguides, such as one or two waveguides, may be required that can support the propagation of multiple (such as three) different color image components (eg, red, green, and blue image components) .

For wearable computing systems that prioritize power consumption, it may be necessary to increase or maximize the luminous flux of the virtual image light. In addition, it may also be desirable to manufacture a system that increases or maximizes the visibility of the external environment to the wearer of the wearable computing system, for example, to facilitate eye contact with other people. There may also be a need for wearers of wearable computing systems or operators of mixed or augmented reality systems to be able to perceive the real world with as little or as little attenuation as possible to avoid hazards and facilitate workday comfort and functionality. Without relying on any particular theory, as the number of optical interfaces between the wearer's eyes and the real world increases, the transmittance of light from the external environment (eg, the real world) may decrease and/or be impaired . For this additional reason, in the waveguide stack of the eyepiece located between the wearer's eyes and the real world, it may be desirable to reduce or minimize the waveguide layers in the waveguide and/or other sources of light that can scatter and/or absorb light from the external environment. Number of optical elements.

Additionally, generally higher indices of refraction provide a larger field of view. Thus, in some designs described herein, the substrate may have an index of refraction of about 1.79 or higher. One such material is lithium niobate (LiNbO3 ₎ , a crystalline material available in thin wafers with a refractive index of about 2.3 in visible wavelengths. Another high refractive index material contemplated in this application is silicon carbide (SiC). SiC is a high refractive index material that at least partially transmits visible light. Thus, one or more waveguides comprising SiC can be integrated into a display device (eg, incorporated into an eyepiece of a head mounted display device). Due to the high index of refraction, two or more differently colored light propagating through a waveguide comprising SiC via total internal reflection can be emitted towards a viewer with a wide field of view. Waveguides comprising SiC may have other advantages of being scratch resistant and/or more difficult to break due to high stiffness coefficients (eg, about 9 to 10 Mohs), which may be advantageous for eyeglasses that are susceptible to drops or improper handling.

Accordingly, various embodiments described herein include eyepieces having a waveguide including a high index of refraction material (eg, a material with an index of refraction greater than glass and/or a material with an index of refraction greater than or equal to about 1.79), the eyepiece Guided propagation of multiple image components of different colors (eg, red, green, and blue image components) in a single waveguide or in two waveguides may be supported, with at least one waveguide supporting guided propagation of both color components. For example, two or more optical flows of different colors that contain image information (eg, red, green, and blue image streams that contain image information) can be coupled into a material that includes a refractive index greater than about 1.79 and/or 2.2 ( such as lithium niobate) such that the optical fluxes propagate within the waveguide via total internal reflection. Additionally, a display device that includes one or more waveguides having a high index of refraction material (eg, a material with an index of refraction greater than that of glass and/or a material with an index of refraction greater than or equal to about 1.79) may have a larger field of view than a display device including one or more A field of view of a display device of a plurality of glass waveguides or one or more waveguides having a material having an index of refraction less than about 1.79.

Accordingly, various embodiments of the display devices described herein include one or more waveguides that include a high index of refraction material (eg, a material with an index of refraction greater than that of glass and/or an index of refraction greater than or equal to about 1.79) materials), the display device can efficiently couple red, green, and blue image light emitted from an imaging system (e.g., a microdisplay and/or projector) and project toward a viewer with an increased field of view Red, green and blue images. For example, in some embodiments of the display devices described herein, a single waveguide comprising a high index of refraction material (eg, a material with an index of refraction greater than glass and/or a material with an index of refraction greater than or equal to about 1.79) may be effective Ground coupling into two colors, such as red and green or green and blue or red and blue image light or image components emitted from an imaging system (eg, a microdisplay and/or projector), and with an increased field of view These images (eg, red and green or green and blue or red and blue images) are projected towards the viewer. In some embodiments of the display devices described in this application, a single waveguide comprising a high index of refraction material (eg, a material with an index of refraction greater than glass and/or a material with an index of refraction greater than or equal to about 1.79) can effectively couple into three colors, such as red, green, and blue image light or image components emitted from an imaging system (eg, a microdisplay and/or a projector), and project these images toward a viewer with an increased field of view (eg, a microdisplay and/or projector) red, green and blue images).

Reference will now be made to the drawings, wherein like reference numerals refer to like parts throughout.

FIG. 2 shows an example of a wearable display system 60 . Display system 60 includes display 70 , and various mechanical and electronic modules and systems that support the functionality of display 70 . Display 70 may be coupled to frame 80 , which may be worn by display system user or viewer 90 and configured to position display 70 in front of user 90 . In some embodiments, the display 70 may be considered glasses. In some embodiments, speaker 100 is coupled to frame 80 and is configured to be positioned near the ear canal of user 90 (in some embodiments, another speaker (not shown) may optionally be positioned in the user's ear canal) near the other ear canal to provide stereo/shapeable sound control). The display system may also include one or more microphones 110 or other devices that detect sound. In some embodiments, the microphone is configured to allow the user to provide input or commands to the system 60 (eg, selection of voice menu commands, natural language questions, etc.) and/or may allow communication with other persons (eg, with other persons who like the display system) user) for audio communication. Microphones may also be configured as peripheral sensors to collect audio data (eg, sounds from the user and/or the environment). In some embodiments, the display system may also include peripheral sensors 120a, which may be separate from the frame 80 and attached to the body of the user 90 (eg, on the head, torso, limbs, etc. of the user 90). In some embodiments, peripheral sensor 120a may be configured to acquire data indicative of the physiological state of user 90 . For example, sensor 120a may be an electrode.

With continued reference to FIG. 2, display 70 is operably coupled to local data processing module 140 via communication link 130, such as via a wired lead or wireless connection, which may be mounted in various configurations, such as fixedly attached to frame 80, fixedly attached to a helmet or hat worn by the user, embedded in a headset, or otherwise removably attached to user 90 (eg, in a backpack configuration, in a strap-coupled configuration) . Similarly, sensor 120a may be operably coupled to local processing and data module 140 through communication link 120b, such as through a wired lead or wireless connection. Local processing and data module 140 may include a hardware processor and digital memory, such as non-volatile memory (eg, flash memory or hard drive), both of which may be used to assist in processing, caching, and storing data. These data include: a) data captured from sensors such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, gyroscopes, and/or other sensors disclosed herein; and/or b) data acquired and/or processed using remote processing module 150 and/or remote data repository 160 (including data about virtual content), which may be communicated to display 70 after such processing or retrieval has been performed. Local processing and data module 140 may be operably coupled to remote processing module 150 and remote data repository 160 by communication links 170, 180, such as via wired or wireless communication links, such that these remote modules 150, 160 are operably coupled to each other and available as resources to local processing and data modules 140 . In some embodiments, the local processing and data module 140 may include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a radio, and/or a gyroscope. In some other embodiments, one or more of these sensors may be attached to frame 80, or may be a separate structure that communicates with local processing and data module 140 through wired or wireless communication paths.

With continued reference to FIG. 2, in some embodiments, remote processing module 150 may include one or more processors configured to analyze and process data and/or image information. In some embodiments, the remote data repository 160 may include a digital data storage facility available through the Internet or other network configuration in a "cloud" resource configuration. In some embodiments, remote data repository 160 may include one or more remote servers that provide information to local processing and data module 140 and/or remote processing module 150, such as for generating augmented reality content information. In some embodiments, all data is stored and all computations are performed in the local processing and data module, allowing fully autonomous use from remote modules.

Referring now to FIG. 3, the perception of an image as "three-dimensional" or "3-D" can be accomplished by providing a slightly different presentation of the image to each eye of the viewer. Figure 3 shows a conventional display system for simulating three-dimensional imagery for a user. Two distinct images 190, 200 are output to the user, one image for each eye 210, 220. The images 190, 200 are spaced a distance 230 from the eyes 210, 220 along an optical or z-axis that is parallel to the viewer's line of sight. The images 190, 200 are flat and the eyes 210, 220 can focus on the images by assuming a single accommodation state. Such 3D display systems rely on the human visual system to synthesize the images 190, 200 to provide a sense of depth and/or scale of the synthesized image.

However, it should be appreciated that the human visual system is more complex and more challenging to provide a realistic sense of depth. For example, many viewers of conventional "3-D" display systems find such systems uncomfortable or incapable of perceiving depth at all. Without being bound by theory, it is believed that a viewer of an object may perceive the object as "three-dimensional" due to the combination of vergence and accommodation. The vergence motion of the two eyes relative to each other (ie, the rotation of the eye fixed on the subject to bring the pupils closer or further away from each other to bring the eyes' vision together) is closely related to the focusing (or "accommodation") of the lens and pupil of the eye. In the resting situation, changing the focus of the eye's lens or adjusting the eye to change focus from one object to another at a different distance will automatically result in a vergence match to the same distance according to a relationship known as the "accommodation-vergence reflex" changes, and pupil dilation or constriction. Likewise, in the resting situation, vergence changes will trigger matching changes in the accommodation of lens shape and pupil size. As described herein, many stereoscopic or "3D" display systems display a scene to each eye using slightly different renderings (and thus slightly different images) so that the human visual system perceives three-dimensional perspective. However, these systems are uncomfortable for many viewers, as they in particular only provide different representations of the scene, but the eye sees all image information in a single accommodation state, and acts in violation of the "accommodation-vergence reflex". A display system that provides a better match between adjustment and vergence can result in a more realistic and comfortable 3D image simulation.

4 illustrates aspects of a method of simulating a three-dimensional imagery using multiple depth planes. Referring to Figure 4, objects at different distances relative to the eyes 210, 220 on the z-axis are accommodated by the eyes 210, 220 to bring these objects into focus. The eyes 210, 220 exhibit specific states of accommodation for convergence at different distances along the z-axis. Accordingly, a particular accommodation state may be considered to be associated with a particular one of the depth planes 40, with an associated focal length such that when the eye is in accommodation for a particular depth plane, the object or portion of the object in that particular depth plane is in focus. In some embodiments, three-dimensional imaging may be simulated by providing a different representation of the image for each eye 210, 220, and also by providing a different representation of the image corresponding to each depth plane. Although shown separated for clarity of illustration, it should be understood that the fields of view of the eyes 210, 220 may overlap, eg, as the distance along the z-axis increases. Furthermore, although shown flat for ease of illustration, it should be understood that the profile of the depth plane may be curved in physical space such that all features in the depth plane are in focus when the eye is in a particular accommodation state.

The distance between the object and the eye 210 or 220 can also change the amount of divergence of light from the object, as seen by the eye. 5A to 5C show the relationship between distance and ray divergence. The distances between the subject and the eye 210 are represented by distances R1 , R2 and R3 in decreasing order. As shown in Figures 5A to 5C, as the distance to the object decreases, the light rays become more divergent. As the distance increases, the light becomes more collimated. In other words, the light field produced by a point (an object or part of an object) can be considered to have a spherical wavefront curvature that is a function of the point's distance from the user's eye. The curvature increases as the distance between the object and the eye 210 decreases. Therefore, at different depth planes, the degree of divergence of light rays is also different, and the degree of divergence increases as the distance between the depth plane and the viewer's eye 210 decreases. Although only a single eye 210 is shown for clarity of illustration in FIGS. 5A-5C and other figures herein, it should be understood that discussions about eye 210 may apply to both eyes 210 and 220 of a viewer.

Without being bound by theory, it is believed that the human eye can generally interpret a limited number of depth planes to provide a sense of depth. Thus, a highly confident perceptual depth simulation can be achieved by providing the eye with different representations of images corresponding to each of these limited number of depth planes. Different presentations can be individually focused by the viewer's eyes, thereby facilitating eye accommodation required to bring different image features of the scene into focus on different depth planes and/or based on the observation that different image features on different depth planes are in loss. Jiaolai provides users with in-depth clues.

Figure 6 shows an example of a waveguide stack for outputting image information to a user. Display system 250 includes a waveguide stack or stacked waveguide assembly 260 that can be used to provide three-dimensional perception to the eye/brain using a plurality of waveguides 270 , 280 , 290 , 300 , 310 . In some embodiments, the display system 250 is the system 60 of FIG. 2, some portions of which are schematically shown in FIG. 6 in greater detail. For example, the waveguide assembly 260 may be part of the display 70 of FIG. 2 . It will be appreciated that, in some embodiments, display system 250 may be considered a light field display. Additionally, the waveguide assembly 260 may also be referred to as an eyepiece.

With continued reference to Figure 6, the waveguide assembly 260 may also include a plurality of features 320, 330, 340, 350 between the waveguides. In some embodiments, features 320, 330, 340, 350 may be one or more lenses. The waveguides 270, 280, 290, 300, 310 and/or the plurality of lenses 320, 330, 340, 350 may be configured to transmit image information to the eye at various levels of wavefront curvature or ray divergence. Each waveguide level can be associated with a particular depth plane and can be configured to output image information corresponding to that depth plane. Image injection devices 360, 370, 380, 390, 400 can be used as light sources for the waveguides and can be used to inject image information into waveguides 270, 280, 290, 300, 310, as described herein, waveguides 270, 280, 290, Each of 300 , 310 may be configured to distribute incident light over each respective entire waveguide for output towards the eye 210 . Light exits the output surfaces 410, 420, 430, 440, 450 of the image injection devices 360, 370, 380, 390, 400 and is injected into the corresponding input surfaces 460, 470, 310 of the waveguides 270, 280, 290, 300, 310, Within 480, 490, 500. In some embodiments, each of the input surfaces 460, 470, 480, 490, 500 may be the edge of the corresponding waveguide, or may be part of the major surface of the corresponding waveguide (ie, directly facing the world 510 or viewing one of the waveguide surfaces of the user's eye 210). In some embodiments, a single beam (eg, a collimated beam) may be injected into each waveguide to output the entire field of cloned collimated beams to correspond to the depth plane associated with a particular waveguide A specific angle (and amount of divergence) of is directed towards the eye 210. In some embodiments, a single one of the image injection devices 360, 370, 380, 390, 400 may be associated with multiple (eg, three) of the waveguides 270, 280, 290, 300, 310 and inject light into the Within multiple (eg, three) of the waveguides 270 , 280 , 290 , 300 , 310 .

In some embodiments, the image injection devices 360, 370, 380, 390, 400 are separate displays, each display generating image information for injection into the corresponding waveguides 270, 280, 290, 300, 310, respectively. In some other embodiments, the image injection device 360, 370, 380, 390, 400 is the output of a single multiplexed display that can pipe the image information via one or more optical conduits, such as fiber optic cables, for example is transmitted to each of the image injection devices 360 , 370 , 380 , 390 , 400 . It will be appreciated that the image information provided by the image injection devices 360, 370, 380, 390, 400 may include light of different wavelengths or colors (eg, different component colors as discussed herein).

In some embodiments, the light injected into the waveguides 270, 280, 290, 300, 310 is provided by a light projection system 520 that includes a light module 540, which may include light such as light emitting diodes (LEDs) launcher. Light from light module 540 may be directed and modified by light modulator 530 (eg, a spatial light modulator) via beam splitter 550 . The light modulator 530 may be configured to vary the perceived intensity of light injected into the waveguides 270 , 280 , 290 , 300 , 310 . Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays. It will be appreciated that image injection devices 360, 370, 380, 390, 400 are shown schematically, which in some embodiments may represent different light paths and locations in a common projection system that is configured To output light into an associated one of the waveguides 270 , 280 , 290 , 300 , 310 .

In some embodiments, display system 250 may be a scanning fiber display that includes one or more scanning fibers configured to connect the Light is projected onto one or more of the waveguides 270 , 280 , 290 , 300 , 310 and finally onto the eye 210 of the viewer. In some embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may schematically represent a single scanning fiber or scanning fiber bundle configured to inject light into the waveguide 270, within one or more of 280, 290, 300, 310. In some other embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may schematically represent a plurality of scanning fibers or a plurality of scanning fiber bundles in which Each of the are configured to inject light into an associated one of the waveguides 270 , 280 , 290 , 300 , 310 . It should be appreciated that one or more optical fibers may be configured to transmit light from the light module 540 to the one or more waveguides 270 , 280 , 290 , 300 , 310 . It will be appreciated that one or more intermediate optical structures may be provided between the one or more scanning fibers and the one or more waveguides 270, 280, 290, 300, 310, for example to redirect light emerging from the scanning fibers to a or multiple waveguides 270, 280, 290, 300, 310.

The controller 560 controls the operation of one or more of the stacked waveguide assemblies 260 , including the operation of the image injection devices 360 , 370 , 380 , 390 , 400 , the light source 540 and the light modulator 530 . In some embodiments, controller 560 is part of local data processing module 140 . Controller 560 includes programming (eg, instructions in a non-transitory medium) that adjusts the timing and provision of image information to waveguides 270 , 280 , 290 , 300 , 310 according to, eg, any of the various schemes disclosed herein . In some embodiments, the controller may be a single integrated device, or a distributed system connected by wired or wireless communication channels. In some embodiments, controller 560 may be part of processing module 140 or 150 (FIG. 2).

With continued reference to Figure 6, the waveguides 270, 280, 290, 300, 310 may be configured to propagate light within each respective waveguide by total internal reflection (TIR). The waveguides 270, 280, 290, 300, 310 may each be planar or have another shape (eg, curved) having major top and bottom surfaces and extending between these major top and bottom surfaces. edge. In the configuration shown, the waveguides 270, 280, 290, 300, 310 may each include an out-coupling optical element 570, 580, 590, 600, 610 that is configured Image information is output to the eye 210 in order to extract light from the waveguides by redirecting light propagating within each respective waveguide out of the waveguides. The extracted light may also be referred to as outcoupling light, and the outcoupling optical element may also be referred to as a light extraction optical element. Where light propagating within the waveguide illuminates the light extraction optics, the extracted light beam may be output by the waveguide. The outcoupling optical elements 570, 580, 590, 600, 610 may be, for example, gratings that include diffractive optical features discussed further herein. Although the outcoupling optical elements 570, 580, 590, 600, 610 are shown disposed at the bottom major surfaces of the waveguides 270, 280, 290, 300, 310 for ease of description and clarity of delineation, in some embodiments, As discussed further herein, outcoupling optical elements 570 , 580 , 590 , 600 , 610 may be disposed on top and/or bottom major surfaces, and/or may be disposed directly on waveguides 270 , 280 , 290 , 300 , 310 in the body. In some embodiments, outcoupling optical elements 570 , 580 , 590 , 600 , 610 may be formed in layers of material attached to the transparent substrate, thereby forming waveguides 270 , 280 , 290 , 300 , 310 . In some other embodiments, the waveguides 270, 280, 290, 300, 310 may be a single piece of material, and the outcoupling optical elements 570, 580, 590, 600, 610 may be formed on the surface of the piece of material and/or inside the block of material.

With continued reference to Figure 6, as discussed herein, each waveguide 270, 280, 290, 300, 310 is configured to output light to form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye may be configured to deliver collimated light (which is injected into such a waveguide 270 ) to the eye 210 . The collimated light may represent the optical infinity focal plane. The next ascending waveguide 280 may be configured to emit collimated light that propagates through the first lens 350 (eg, a negative lens) before it can reach the eye 210 . Such a first lens 350 may be configured to produce a slightly convex wavefront curvature such that the eye/brain interprets light from the next ascending waveguide 280 as coming from a first focal plane closer to the eye 210 from optical infinity inward . Similarly, the next third ascending waveguide 290 has its output light propagating through the first lens 350 and the second lens 340 before reaching the eye 210 . The combined optical power of the first lens 350 and the second lens 340 can be configured to produce another wavefront curvature increment such that the eye/brain interprets light from the third waveguide 290 as coming from optical infinity further inward. Light from the second focal plane close to the person and not from the next upstream waveguide 280 .

The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, with the highest waveguide 310 in the stack sending its output through all lenses between it and the eye to obtain a total power representing the focal plane closest to the human . To compensate for the lens stacks 320, 330, 340, 350 when viewing/interpreting light from the world 510 on the other side of the stacked waveguide assembly 260, a compensation lens layer 620 may be provided at the top of the stack to compensate for the lens stacks 320 below , 330, 340, 350 total power. This configuration provides as many perceptual focal planes as there are waveguide/lens pairings available. Both the outcoupling optics of the waveguide and the focusing aspects of the lens may be static (ie, not dynamic or electrically active). In some alternative embodiments, one or both of them may be dynamic through the use of electroactive features.

In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 may be configured to output image sets to the same depth plane, or multiple subsets of waveguides 270, 280, 290, 300, 310 may be configured to output image sets Output to the same multiple depth planes, one image set per depth plane. This can provide the advantage of forming a stitched image to provide an extended field of view in those depth planes.

With continued reference to Figure 6, the out-coupling optical elements 570, 580, 590, 600, 610 can be configured to both redirect light out of their respective waveguides and with the appropriate amount of divergence or collimation for the particular depth plane associated with the waveguides degrees to output the light. Thus, waveguides with different associated depth planes may have different configurations of outcoupling optical elements 570, 580, 590, 600, 610 depending on the associated depth plane to Different divergences output light. In some embodiments, the light extraction optical elements 570, 580, 590, 600, 610 may be volume features or surface features that may be configured to output light at specific angles. For example, the light extraction optical elements 570, 580, 590, 600, 610 may be volume holograms, surface holograms and/or diffraction gratings. In some embodiments, features 320, 330, 340, 350 may not be lenses. Rather, they may be merely spacers (eg, cladding and/or structures for forming air gaps).

In some embodiments, outcoupling optical elements 570, 580, 590, 600, 610 are diffractive features that form a diffractive pattern, or "diffractive optical elements" (also referred to herein as "DOEs"). Preferably, the DOE has sufficiently low diffraction efficiency so that only a portion of the beam is deflected away toward the eye 210 by each intersection of the DOE, while the remainder continues to travel through the waveguide via TIR. Thus, the light carrying the image information is split into a number of related outgoing beams that exit the waveguide at multiple locations, resulting in a comparable amount of light toward the eye 210 for a particular collimated beam bouncing around within the waveguide. Uniform exit pattern.

In some embodiments, one or more DOEs may be switchable between an "on" state for aggressive diffraction and an "off" state for insignificant diffraction. For example, a switchable DOE can include a polymer dispersed liquid crystal layer, wherein the droplets include a diffraction pattern in the host medium, and the index of refraction of the droplets can be switched to substantially match the index of refraction of the host material (in this case, the pattern does not appreciably diffract incident light) or the droplets can be switched to an index of refraction that does not match that of the host medium (in which case the pattern actively diffracts incident light).

In some embodiments, a camera assembly 630 (eg, a digital camera, including visible and infrared cameras) may be provided to capture images of the eye 210 and/or tissue surrounding the eye 210, eg, to detect user input and/or monitor the user's physiological state. As used herein, a camera can be any image capture device. In some embodiments, camera assembly 630 can include an image capture device and a light source to project light (eg, infrared light) to the eye, which can then be reflected by the eye and detected by the image capture device. In some embodiments, camera assembly 630 may be attached to frame 80 ( FIG. 2 ) and may be in electrical communication with processing modules 140 and/or 150 that may process image information from camera assembly 630 . In some embodiments, one camera assembly 630 may be used for each eye to monitor each eye separately.

Referring now to FIG. 7, an example of an outgoing beam output by a waveguide is shown. One waveguide is shown, but it will be understood that other waveguides in waveguide assembly 260 (FIG. 6), which include multiple waveguides, may serve a similar function. Light 640 is injected into waveguide 270 at input surface 460 of waveguide 270 and propagates within waveguide 270 by TIR. At the point where light 640 strikes DOE 570, a portion of the light exits the waveguide as outgoing beam 650. The exit beams 650 are shown as being substantially parallel, but as discussed herein, they may also be redirected to propagate to the eye 210 at an angle (eg, to form a diverging exit beam) depending on the angle associated with the waveguide 270 the depth plane. It will be appreciated that a substantially parallel outgoing beam may be indicative of a waveguide with out-coupling optics that couple the light out to form a depth plane that appears to be disposed at a greater distance (eg, optical infinity) from the eye 210 image on. Other waveguides or other sets of out-coupling optics may output a more diverging outgoing beam pattern that would require the eye 210 to accommodate a closer distance to focus it on the retina, and would be interpreted by the brain as coming from a Optical infinity is light at a distance closer to the eye 210 .

In some embodiments, a full-color image may be formed at each depth plane by overlaying images in each of the component colors (eg, three or more component colors). Figure 8 shows an example of a stacked waveguide assembly where each depth plane includes an image formed using multiple different component colors. The illustrated embodiment shows depth planes 240a to 240f, although greater or lesser depths are also contemplated. Each depth plane may have three or more component color images associated with it, including: a first image G of a first color; a second image R of a second color; and a third image B of a third color. The different depth planes are indicated in the figures by the different diopters (dpt) following the letters G, R and B. For example, the number following each of these letters indicates the diopter (1/m), or the inverse of the distance of the depth plane from the viewer, and each box in the figure represents a separate component color image. In some embodiments, to account for differences in the eye's focusing of different wavelengths of light, the precise placement of the depth planes for the different component colors may vary. For example, different component color images for a given depth plane may be placed on the depth plane corresponding to different distances from the user. Such an arrangement may increase visual acuity and user comfort and/or may reduce chromatic aberration.

In some embodiments, light for each component color may be output by a single dedicated waveguide, and thus, each depth plane may have multiple waveguides associated with it. In such an embodiment, each box in the figures including the letter G, R or B may be understood to represent a separate waveguide, and three waveguides may be provided for each depth plane, wherein three waveguides are provided for each depth plane Component color image. Although the waveguides associated with each depth plane are shown in this figure adjacent to each other for ease of description, it will be appreciated that in a physical device, the waveguides could all be arranged in a stack with one waveguide per layer. In some other embodiments, multiple component colors may be output by the same waveguide, such that, for example, only a single waveguide may be provided for each depth plane.

With continued reference to Figure 8, in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light (including magenta and blue).

It will be understood that references throughout this disclosure to light of a given color will be understood to include light that is perceived by a viewer as having one or more wavelengths within the wavelength range of light of the given color. For example, red light can include one or more wavelengths of light in the range of about 620nm to 780nm, green light can include one or more wavelengths of light in the range of about 492nm to 577nm, and blue light can include light in the range of about 435nm to 577nm One or more wavelengths of light in the 493nm range.

In some embodiments, light source 540 (FIG. 6) may be configured to emit light at one or more wavelengths (eg, infrared and/or ultraviolet wavelengths) that are outside the visual perception range of a viewer. In addition, the coupling in, coupling out, and other light redirecting structures of the waveguides of the display 250 may be configured to direct the light from the display and emit it toward the user's eye 210, eg, for imaging and/or user excitation applications.

Referring now to FIG. 9A, in some embodiments, it may be desirable to redirect light impinging on a waveguide to couple the light into the waveguide. Coupling optics can be used to redirect and couple light into its corresponding waveguide. FIG. 9A shows a cross-sectional side view of an example of a multiple or stacked waveguide group 660, where each stacked waveguide includes an in-coupling optical element. The waveguides may each be configured to output one or more different wavelengths of light, or one or more different wavelength ranges of light. It will be appreciated that stack 660 may correspond to stack 260 ( FIG. 6 ) and that the waveguides of stack 660 shown may correspond to a portion of multiple waveguides 270 , 280 , 290 , 300 , 310 , except from image injection devices 360 , 370 Light of one or more of , 380, 390, 400 is injected into the waveguide from where it is desired to redirect the light for incoupling.

The illustrated stacked waveguide set 660 includes waveguides 670 , 680 and 690 . The waveguide 670 is located before or closer to the image light source than the waveguide 680, and the waveguide 690 is located after or further from the image source than the waveguide 680. Each waveguide includes an associated in-coupling optical element (which may also be referred to as a light input region on the waveguide), eg, in-coupling optical element 700 disposed on a major surface (eg, top major surface) of waveguide 670, In-coupling optical element 710 on a major surface (eg, top major surface) of waveguide 680 and in-coupling optical element 720 disposed on a major surface (eg, top major surface) of waveguide 690 . In some embodiments, one or more of the in-coupling optical elements 700, 710, 720 may be disposed on the bottom major surface of the respective waveguide 670, 680, 690 (particularly on the one or more in-coupling optical elements is the case of a reflective deflecting optical element). As shown, the in-coupling optical elements 700, 710, 720 may be positioned on the top major surfaces of their respective waveguides 670, 680, 690 (or the top of the next downstream waveguide), particularly where those in-coupling optical elements are In the case of transmissive deflection optics. In some embodiments, the in-coupling optical elements 700 , 710 , 720 may be disposed in the body of the respective waveguides 670 , 680 , 690 . In some embodiments, as discussed herein, the coupling optical elements 700, 710, 720 are wavelength selective such that they selectively redirect one or more wavelengths of light while transmitting other wavelengths of light. Although shown on one side or corner of their respective waveguides 670, 680, 690, it will be appreciated that in some embodiments, the in-coupling optical elements 700, 710, 720 may be disposed on their respective waveguides 670, 680, 690 in other areas.

As shown, the in-coupling optical elements 700, 710, 720 may be laterally offset from each other. In some embodiments, each in-coupling optical element may be offset such that it receives light without the light propagating through the other in-coupling optical element light. For example, each in-coupling optical element 700, 710, 720 can be configured to receive light from a different image injection device 360, 370, 380, 390, and 400, as shown in FIG. 6, and can be combined with other in-coupling optical elements 700 , 710 , 720 are separated (eg, laterally spaced) such that they receive substantially no light from other ones of the in-coupled optical elements 700 , 710 , 720 .

Each waveguide also includes associated light distributing elements, eg, light distributing element 730 disposed on a major surface (eg, top major surface) of waveguide 670, Light distributing element 740 , and light distributing element 750 disposed on a major surface (eg, top major surface) of waveguide 690 . In some other embodiments, light distributing elements 730, 740, 750 may be disposed on the bottom major surfaces of associated waveguides 670, 680, 690, respectively. In some other embodiments, the light distributing elements 730, 740, 750 may be disposed on the top and bottom major surfaces of the associated waveguides 670, 680, 690, respectively, or the light distributing elements 730, 740, 750 may be disposed separately On different top and bottom major surfaces in different associated waveguides 670 , 680 , 690 .

The waveguides 670, 680, 690 may be spaced and separated by, for example, layers of gas, liquid and/or solid material. For example, layer 760a may separate waveguides 670 and 680; layer 760b may separate waveguides 680 and 690, as shown. In some embodiments, layers 760a and 760b are formed of a low refractive index material (ie, a material having a lower refractive index than the material forming the immediately adjacent ones of waveguides 670, 680, 690). Preferably, the refractive index of the material forming the layers 760a, 760b is 0.05 or greater than the refractive index of the material forming the waveguides 670, 680, 690, or 0.10 or less than the refractive index of the material forming the waveguides 670, 680, 690. Advantageously, the low index layers 760a, 760b may act as cladding layers that facilitate total internal reflection (TIR) of light through the waveguides 670, 680, 690 (eg, TIR between the top and bottom major surfaces of each waveguide) ). In some embodiments, layers 760a, 760b are formed of air. Although not shown, it will be understood that the top and bottom of the illustrated waveguide group 660 may include immediately adjacent cladding.

Preferably, for ease of manufacture and for other reasons, the waveguides 670, 680, 690 are formed of similar or identical materials, and the layers 760a, 760b are formed of similar or identical materials. In some embodiments, the materials forming the waveguides 670, 680, 690 may be different between one or more waveguides, and/or the materials forming the layers 760a, 760b may be different, while still maintaining the various refractions described above rate relationship.

With continued reference to FIG. 9A , light rays 770 , 780 , 790 are incident on waveguide group 660 . It will be appreciated that light rays 770, 780, 790 may be injected into waveguides 670, 680, 690 by one or more image injection devices 360, 370, 380, 390, 400 (FIG. 6). Light rays 770, 780, 790 may constitute image light, light encoded with image information. For example, the light may have been spatially modulated, or otherwise provided with different intensities and/or different wavelengths at different locations, eg, to form pixels that make up an image.

In some embodiments, the light rays 770, 780, 790 have different properties, eg, different wavelengths or different wavelength ranges, which may correspond to different colors. The in-coupling optical elements 700 , 710 , 720 each deflect incident light such that the light propagates through a respective one of the waveguides 670 , 680 , 690 by TIR. In some embodiments, the in-coupling optical elements 700, 710, 720 each selectively deflect one or more specific wavelengths of light, while transmitting other wavelengths to the underlying waveguide and associated in-coupling optical elements.

For example, in-coupling optical element 700 may be configured to deflect light 770 having a first wavelength or range of wavelengths while transmitting light 780 and 790 having different second and third wavelengths or ranges of wavelengths, respectively. The transmitted light 780 impinges on and is deflected by an in-coupling optical element 710 that is configured to deflect light of a second wavelength or wavelength range. Light ray 790 is deflected by in-coupling optical element 720 configured to selectively deflect light of a third wavelength or range of wavelengths.

With continued reference to FIG. 9A, the deflected rays 770, 780, 790 are deflected so that they propagate through the corresponding waveguides 670, 680, 690; that is, the coupled optical elements 700, 710, 720 of each waveguide The light is deflected into the corresponding waveguides 670, 680, 690 to couple the light into the corresponding waveguides. Light rays 770, 780, 790 are deflected at angles that cause the light to propagate through the respective waveguides 670, 680, 690 by TIR. Light rays 770, 780, 790 propagate by TIR through the respective waveguides 670, 680, 690 until impinging on the respective light distributing elements 730, 740, 750 of the waveguides.

Referring now to FIG. 9B, a perspective view of an example of the multiple stacked waveguides of FIG. 9A is shown. As described above, in-coupled light rays 770, 780, 790 are deflected by in-coupled optical elements 700, 710, 720, respectively, and then propagate through TIR within waveguides 670, 680, 690, respectively. Then, the light rays 770, 780, 790 impinge on the light distribution elements 730, 740, 750, respectively. Light distributing elements 730, 740, 750 deflect light rays 770, 780, 790 so that they propagate towards outcoupling optical elements 800, 810, 820, respectively.

In some embodiments, the light distributing elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPE deflects or distributes light to the outcoupling optics 800, 810, 820, and in some embodiments may also increase the beam or spot size of the light as it travels to the outcoupling optics. In some embodiments, the light distributing elements 730 , 740 , 750 may be omitted, and the in-coupling optical elements 700 , 710 , 720 may be configured to deflect light directly to the out-coupling optical elements 800 , 810 , 820 . E.g. Referring to Figure 9A, light distributing elements 730, 740, 750 may be replaced with outcoupling optical elements 800, 810, 820, respectively. In some embodiments, the outcoupling optical elements 800, 810, 820 are exit pupils (EP) or exit pupil expanders (EPE), which direct light in the viewer's eye 210 (FIG. 7). It will be appreciated that the OPE can be configured to increase the size of the eye movement range on at least one axis and the EPE can be configured to increase the size of the eye movement range on an axis that intersects (eg, is orthogonal to) the axis of the OPE. For example, each OPE can be configured to redirect a portion of the light impinging on the OPE to the EPE of the same waveguide, while allowing the remainder of the light to continue propagating down the waveguide. When the OPE is illuminated again, another portion of the remaining light is redirected to the EPE, and the remainder of this portion continues to propagate further down the waveguide, and so on. Likewise, when the EPE is illuminated, a portion of the illuminated light is directed out of the waveguide towards the user, the remainder of the light continues to propagate through the waveguide until the EP is illuminated again, at which point another portion of the illuminated light is directed out of the waveguide, and so on. Thus, whenever a portion of the light is redirected by an OPE or EPE, a single coupled-in beam can be "duplicated", creating a field of cloned beams, as shown in Figure 6. In some embodiments, the OPE and/or EPE may be configured to vary the size of the beam.

9A and 9B, in some embodiments, waveguide set 660 includes waveguides 670, 680, 690 for each component color; coupling optical elements 700, 710, 720; light distributing elements (eg, OPEs) 730, 740, 750; and outcoupling optical elements (eg, EP) 800, 810, 820. The waveguides 670, 680, 690 may be stacked with air gaps/claddings between each waveguide. In-coupling optics 700, 710, 720 redirect or deflect incident light (through different coupling-in optics that receive light of different wavelengths) into their waveguides. The light then propagates at an angle that will result in TIR within the respective waveguides 670, 680, 690. In the example shown, light ray 770 (eg, blue light) is deflected by first in-coupling optical element 700 in the manner previously described, and then continues to bounce down the waveguide, interacting with light distributing element (eg, OPE) 730, It then interacts with outcoupling optical element (eg, EP) 800 . Light rays 780 and 790 (eg, green light and red light, respectively) will propagate through waveguide 670 , ray 780 impinging on and being deflected by in-coupling optical element 710 . Light ray 780 then bounces down the waveguide 680 via TIR, continuing to its light distributing element (eg, OPE) 740 , and then continuing to outcoupling optical element (eg, EP) 810 . Finally, light 790 (eg, red light) propagates through the waveguide 690 to impinge on the optical incoupling optical element 720 of the waveguide 690 . The light in-coupling optical element 720 deflects light 790 such that the light propagates by TIR to the light distributing element (eg, OPE) 750 and then to the out-coupling optical element (eg, EP) 820 by TIR. The out-coupling optical element 820 then finally couples the light 790 out to the viewer, who also receives the out-coupled light from the other waveguides 670,680.

9C illustrates a top plan view of an example of the multiple stacked waveguides of FIGS. 9A and 9B. As shown, the waveguides 670, 680, 690 and the associated light distributing elements 730, 740, 750 and associated outcoupling optical elements 800, 810, 820 of each waveguide may be vertically aligned. However, as discussed herein, the in-coupling optical elements 700, 710, 720 are not vertically aligned; instead, the in-coupling optical elements are preferably non-overlapping (eg, laterally spaced as shown in top view). As discussed further herein, this non-overlapping spatial arrangement facilitates one-to-one injection of light from different sources into different waveguides, allowing a particular light source to be uniquely coupled to a particular waveguide. In some embodiments, arrangements comprising non-overlapping spatially separated in-coupling optical elements may be referred to as shifted or divided pupil systems, and in-coupling optical elements within these arrangements may correspond to sub-pupils.

As described above, various embodiments of display system 60 or display system 250 may include waveguides having high refractive index materials. For example, various embodiments of display system 60 or display system 250 may include one or more waveguides having a material having an index of refraction greater than that of glass. In various embodiments of display system 60 or display system 250, one or more waveguides may be included having a material having an index of refraction greater than or equal to about 1.79 and less than or equal to about 4.5. For example, various embodiments of display system 60 or display system 250 may include one or more waveguides of materials having the following indices of refraction: greater than or equal to 1.8 and less than or equal to 2.1, greater than or equal to 2.1 and less than or equal to 2.2, greater than or equal to 2.2 or equal to 2.2 and less than or equal to 2.3, greater than or equal to 2.3 and less than or equal to 2.4, greater than or equal to 2.4 and less than or equal to 2.5, greater than or equal to 2.5 and less than or equal to 2.6, greater than or equal to 2.6 and less than or equal to 2.7, greater than or equal to 2.7 and less than or equal to 2.8, greater than or equal to 2.8 and less than or equal to 2.9, greater than or equal to 2.9 and less than or equal to 3.0, greater than or equal to 3.0 and less than or equal to 3.1, greater than or equal to 3.1 and less than or equal to 3.2, greater than or equal to 3.2 and less than or equal to 3.3, greater than or equal to 3.3 and less than or equal to 3.4, greater than or equal to 3.4 and less than or equal to 3.5, greater than or equal to 3.5 and less than or equal to 3.6, greater than or equal to 3.6 and less than or equal to 3.7, greater than or equal to 3.7 and less than or equal to 3.8, greater than or equal to 3.8 and less than or equal to 3.9, greater than or equal to 3.9 and less than or equal to 4.0, greater than or equal to 4.0 and less than or equal to 4.2, greater than or equal to 4.0 and less than or equal to 4.4, Greater than or equal to 4.0 and less than or equal to 4.5 or any value in any range/sub-range defined by these values. Without loss of generality, the high refractive index materials contemplated in this application may be transparent to visible light. For example, high refractive index materials contemplated in some embodiments of the present application may be configured to transmit visible light in the spectral range between about 450 nm and about 750 nm with greater than or equal to about 80% or 90% efficiency. However, in certain embodiments, Fresnel reflections may occur at the interface of the waveguide.

As described above, the inclusion of a high index of refraction (eg, an index of refraction greater than Various embodiments of display system 60 or display system 250 of one or more waveguides of a material having an index of refraction and/or index of refraction greater than or equal to about 1.79) may have an increased field of view. Furthermore, as described above, multiple colors or wavelengths of light (eg, two or possibly three colors) can be coupled simultaneously into a single waveguide comprising a high index of refraction material. Accordingly, various embodiments of display system 60 or display system 250 may include different waveguides associated with different depth planes. In some embodiments, the waveguides associated with the depth planes may include high refractive index materials such that different colors of incident light, such as three colors (eg, red, green, and blue wavelengths), may be coupled into a single guide within and within the waveguide. Thus, the associated waveguide is capable of projecting a color image including light of different wavelengths (eg, red, green, and blue wavelengths) toward the viewer. Similarly, in some embodiments, one of the waveguides associated with the depth plane may include a high index of refraction material to allow incidence of different colors, such as two colors (eg, red and green or green and blue wavelengths) Light can be coupled into and guided within a single waveguide. Another waveguide associated with the depth plane can be configured such that at least one different color (blue or red, respectively) can be coupled into and guided within a single waveguide. The waveguide may also include a high refractive index material. Thus, the combination of waveguides for this depth plane or depth can project a color image including light of different wavelengths (eg, red, green, and blue wavelengths) toward the viewer. One or more other waveguide configurations can be used for other depth planes or depths. Various high refractive index materials contemplated in this application include, for example, lithium niobate (LiNbO3) with a refractive index of about _2.3 or silicon carbide with a refractive index higher than 2.7, or other similar materials, possibly even with higher refractive indices s material.

As described above, one or more waveguides in various embodiments of display system 60 or display system 250 may include in-coupling optical elements (eg, in-coupling optical elements 700, 710) that couple light into the one or more waveguides , 720) and/or outcoupling optical elements (eg, 570, 580, 590, 800, 810, 820) that couple light out of one or more waveguides. In various embodiments of display system 60 or display system 250, one or more of the waveguides may include light distributing elements (eg, light distributing elements 730, 740, 750). In various embodiments, light distributing elements (eg, light distributing elements 730, 740, 750) may be configured as orthogonal pupil expanders (OPEs) and/or outcoupling elements (eg, 800, 810, 820) may be configured Configured as an Exit Pupil Expander (EPE), or as a Combined Pupil Expander (CPE) that exhibits both orthogonal expansion and outcoupling functions. The eyepiece may include any one or any combination of an In-Coupling Optical Element (ICG), an Orthogonal Pupil Expander (OPE), an Exit Pupil Expander (EPE), and a Combined Pupil Expander (CPE). Therefore, a wide variety of configurations are possible. For example, some eyepieces do not include an orthogonal pupil expander (OPE). The in-coupling optical elements, the out-coupling optical elements and the light distributing elements may include diffractive features. Diffractive optical elements may include microscale and/or nanoscale features. Without loss of generality, in-coupling optical elements, out-coupling optical elements, and/or light distributing elements may be disposed on one or both surfaces (eg, major surfaces) of the waveguide in different embodiments of display system 60 or display system 250. , front and rear surfaces, etc.). For example, various embodiments of waveguides described in this application can have waveguides disposed on both surfaces (eg, main, front, and rear surfaces, etc.), or all on a single surface, or even overlap on a single surface The diffraction structure on the .

The use of one or more waveguides comprising a high index of refraction material (eg, an index of refraction greater than that of glass and/or an index of refraction greater than about 1.79) in viewing optics assembly architectures for mixed reality systems can advantageously provide an optical interface and A waveguide stack with a reduced number of waveguide layers and potentially allowing the use of low-cost, lightweight virtual image focus shifting elements, increasing or maximizing the transparency of the waveguide stack, reducing or minimizing manufacturing costs, or reducing or minimizing the waveguide stack size, weight and/or mass, or potentially any combination of these features.

Accordingly, various embodiments of display systems (eg, head-mounted AR/VR display devices) described in this application include materials having a high index of refraction (eg, an index of refraction greater than 1.79, such as an index of refraction greater than or equal to about 2.3) one or more waveguides. The one or more waveguides include top and bottom major surfaces and a plurality of edges between the top and bottom major surfaces. The one or more waveguides may further include in-coupling optical elements (eg, similar to in-coupling optical elements 700 , 710 , 720 ) and out-coupling optical elements (eg, similar to elements 570 , 580 , 590 , 800 ) , 810, 820 out-coupling optics) configured to couple in different colors of image light emitted from imaging systems (eg, microdisplays and/or projectors), the out-coupling optics being configured To project the coupled light towards the wearer's eyes. In some embodiments, the one or more waveguides may further include light distributing elements (eg, light distributing elements similar to light distributing elements 730, 740, 750). As discussed above, one or more of the in-coupling optical element, the out-coupling optical element, and the light distributing element may include a diffraction grating. In various embodiments, the diffraction grating may include microscale or nanoscale features. Diffraction gratings may include surface or volume features. Without loss of generality, in-coupling optical elements, out-coupling optical elements and light distributing elements may be provided on one or both major surfaces of one or more waveguides.

As described above, in various embodiments of the display systems (eg, head-mounted AR/VR display devices) described in this application, one or more coupling optical elements may be configured to transmit data from an imaging system (eg, a head-mounted AR/VR display device). A microdisplay and/or projector) emits two or more differently colored optical streams containing image information coupled into a material comprising a high refractive index (eg, a refractive index greater than 1.79, eg, a refractive index greater than or equal to about 2.3) Within a single waveguide, the coupled light of different colors propagates within the single waveguide through total internal reflection. For example, in some embodiments, optical fluxes of first, second, and third colors (eg, red, green, and blue) containing image information may be coupled to include a high refractive index (eg, a refractive index greater than 1.79, For example, within one or both waveguides of a material with a refractive index greater than or equal to about 2.3) so that the coupled first, second, and third (eg, red, green, and blue) light passes through total internal reflection in the corresponding waveguides spread within. For example, in some such embodiments, optical fluxes of first, second, and third colors (eg, red, green, and blue) that contain image information may be coupled to include a high index of refraction (eg, an index of refraction greater than 1.79, eg, within a single waveguide of a material with a refractive index greater than or equal to about 2.3).

As described above, light projected from a waveguide that includes a high index of refraction (eg, an index of refraction greater than 1.79, such as an index of refraction greater than or equal to about 2.3) may have an increased field of view through which the light is output by the waveguide, thus , the viewer can see the virtual image content through this field of view. The field of view can vary based on the index of refraction of the waveguide material and the number of wavelengths coupled into the waveguide. Tables 1A and 1B below include when one (1) color or single color, two (2) colors or two colors (eg, green and blue or red and blue) and three (3) colors or three colors Calculated values in degrees for the vertical and horizontal fields of view provided by various waveguide embodiments of the head-mounted AR/VR display device when light (e.g., red, green, and blue) is coupled into the waveguide, The various waveguides include materials having an index of refraction between about 1.73 and about 2.3.

Table 1A: When one (1) color or single color, two (2) colors or two colors (eg, green and blue or red and blue), and three (3) colors or three colors (eg, red , green and blue) light is coupled into the waveguides, calculated in degrees for the vertical and horizontal fields of view provided by various waveguide embodiments of the head-mounted AR/VR display device, which waveguides include refraction Materials with a ratio between about 1.73 and about 2.3.

Table 1B: When one (1) color or single color, two (2) colors or two colors (eg, green and blue or red and blue), and three (3) colors or three colors (eg, red , green and blue) light is coupled into the waveguides, calculated in degrees for the vertical and horizontal fields of view provided by various waveguide embodiments of the head-mounted AR/VR display device, which waveguides include refraction Materials with a ratio between about 1.73 and about 2.3.

Note from Tables 1A and 1B that as the index of refraction of the material of the waveguide increases, the degrees of vertical and horizontal fields of view also increase. For example, depending on one (1) color or single color, two (2) colors or two colors (eg, green and blue or red and blue), and three (3) colors or three colors (eg, red , green and blue) light is coupled into the waveguide, a waveguide comprising a material with an index of refraction greater than about 1.79 has a horizontal field of view greater than about 20.2 degrees and a vertical field of view greater than about 20.2 degrees. Note further from Table 1A that when light of all three (3) colors (eg, red, green, and blue) is coupled into the waveguide, by the various waveguide embodiments of the head-mounted AR/VR display device, the The waveguide includes a material with an index of refraction of about 2.3 (eg, lithium niobate), providing a horizontal and vertical field of view of about 45.9 degrees and 56.1 degrees, respectively, which is about a 70 degree diagonal field of view. Thus, embodiments of eyepieces that include waveguides with materials having a refractive index of about 2.3 (eg, lithium niobate) or higher (eg, silicon carbide) are attractive for obtaining display devices with an increased field of view solution.

In addition to having a high refractive index, lithium niobate has other advantages. For example, lithium niobate is typically available in wafer form, is optically transparent to visible light and has low scattering. Although lithium niobate may not have been previously considered as the material of choice as a substrate material on which large area relief drain grating structures such as those used in ICG, EPE and OPE of mixed reality eyepieces can be fabricated, gratings can be as described herein. Manufactured as described above for use in head mounted displays. One reason that lithium niobate is not particularly desirable as a substrate material on which grating structures for ICG, EPE, and OPE can be fabricated can be attributed, at least in part, to the difficulty in producing large area grating structures economically. The ferroelectric and pyroelectric properties of lithium niobate present difficulties in fabricating large area grating structures using etch masks obtained by sputter deposition and patterning of a resist layer. However, the lithium niobate processing methods described herein can be used to fabricate large-area grating structures. Additional discussion regarding methods of making lithium niobate is included below.

Such high refractive index waveguides may be advantageously included in optical systems for head mounted displays such as shown in FIG. 10 . 10 shows an example of a display system 1000 that includes an imaging system 1001, a waveguide 1003 comprising a high refractive index (eg, refractive index greater than about 1.79) material, and a plurality of variable focus elements 1005a and 1005b. Imaging system 1001 includes projection optics 1009; illumination optics 1011, which provides three colors (eg, red, green, and blue light); and spatial light modulation element 1013, which modulates light emitted from illumination optics 1011 (eg, red, green, and blue light) to form an optical flow that includes image information. Optical flows of three different colors (eg, red, green, and blue) containing image information modulated by the spatial optical modulator are output from a single output pupil of projection optics 1009 . This optical flux of three different colors (eg, red, green, and blue) exiting the single output pupil of projection optics 1009 containing image information is received by one or more in-coupling optical elements associated with waveguide 1003 and Diffraction so that the three-color (eg, red, green, and blue) optical flows comprising image information are coupled into the waveguide 1003 . As discussed above, in various embodiments, one or more of the in-coupling optical elements may be aligned (eg, vertically aligned) with a single output pupil of projection optics 1009 such that in top view, one or more At least a portion of each of the coupling optical elements overlaps the single output pupil of projection optics 1009 .

In some embodiments, imaging system 1001 may include a low-quality compact microdisplay. In some embodiments, the imaging system 1001 may include a dichroic pupil, a closely spaced set of red-green-blue ("RGB") sub-pupils, or an internal pupil (as in MEMs systems, where the pupil is located at at the plane of the scanning mirror). In various embodiments, imaging system 1001 may have similar features to any of the imaging systems discussed below with reference to Figures 11-17B.

The waveguide 1003 may comprise a material with an index of refraction greater than or equal to about 2.3, such as lithium niobate. When the waveguide 1003 includes lithium niobate, the diagonal field of view of light output from the waveguide can be approximately 70° for red, green, and blue wavelengths. In some embodiments, the display system 1000 may include two waveguides instead of a single waveguide 1003 . For example, a first of the two waveguides may be configured to couple into one or two differently colored optical flows (eg, a red image flow, or a red and green image flow) that include image information, and the The second waveguide may be configured to couple into one or two additional optical streams of different colors (eg, blue and green image streams, or blue image streams, respectively) that include image information. In some embodiments in which the first waveguide includes two optical flows of different colors, a second waveguide of the two waveguides may be configured to couple into a different color of optical flow than the first waveguide and a different color from the first waveguide. An optical stream of the same or similar color (eg, green and blue image streams, or red and blue image streams) included in a waveguide.

System 1000 can be configured as an infinity-focused system that presents a viewer or viewer's eyes 1007 with an unpowered view of the real world, and a virtual image at a location beyond infinity. Variable focus elements 1005a and 1005b provide the ability to shift the focal plane of the virtual image. Variable focus element 1005a may be configured as a positive continuously variable focus element and variable focus element 1005b may be configured as a negative continuously variable focus element. In various embodiments, variable focus elements 1005a and 1005b may comprise pairs of liquid-filled variable focus lenses. In some embodiments, variable focus elements 1005a and 1005b may comprise liquid crystal (LC) based pixel programmable Fresnel lens pairs. For the real world viewed through the pair of variable focus elements 1005a and 1005b simultaneously, the negative focusing element 1005b can be configured to shift the virtual image position and the positive focusing element 1005a can be configured to neutralize the power of the negative focusing element 1005b. Light projected from waveguide 1003 traverses only negative focusing element 1005b. Depending on the specific capabilities of the variable focus elements 1005a and 1005b, this method and combination of elements can produce a continuum of focal planes, depth planes, or depths. Example near and far planes are shown in FIG. 10 . The switch or control module schematically illustrates coordinating spatial light modulator 1013 with variable focus elements 1005a and 1005b so that various images are presented at appropriate depths. An integrated stack comprising variable focus elements 1005a and 1005b and a single waveguide 1003 can be made thin enough and low enough mass primarily depending on the ability to miniaturize the variable focus elements 1005a and 1005b. Without loss of generality, when display system 1000 is included in a head mounted display, the integrated stack comprising variable focus elements 1005a and 1005b and single waveguide 1003 may be referred to as an eyepiece. In some embodiments, the eyepiece may be an infinity focusing eyepiece designed to have focus at a distance in at least one state.

The design of the display system 1000 shown in Figure 10 can advantageously provide a substantially small microdisplay, since only a single pupil with color mixing is used, and the shift focus plane is entirely through a liquid lens pair or based on liquid crystal ("LC") of programmable lens pairs complete. However, in some embodiments, the weight of the display system 1000 may also increase due to the increased weight of the liquid lens or programmable Fresnel lens system. Additionally, the use of liquid lenses or programmable Fresnel lens systems may increase optical distortion. Furthermore, the thickness of the integrated stack including waveguide 1003 and variable focus elements 1005a and 1005b may increase due to the frame required to support variable focus elements 1005a and 1005b.

FIG. 11 shows another embodiment of a display system 1100 . Display system 1100 employs imaging system 1001 and waveguide 1003 discussed above. Accordingly, various elements of display system 1100 may be similar to corresponding elements of display system 1000 . In display system 1100, switchable geometric phase (GP) lens stacks, rather than liquid-filled lens pairs or LC-based pixelated programmable Fresnel lens pairs, are used as variable focus elements 1005a and 1005b. Display system 1100 may be thinner and lighter than display system 1000 . However, since the geometric phase (GP) lens stack operates only on polarized light, display system 1100 may include polarizers to filter real-world light entering the system. Introducing a polarizer results in a reduction in the brightness of real-world light entering the system. For example, in some embodiments, the introduction of a polarizer can result in about a 50% reduction in brightness. In some embodiments, combined with other losses from the GP lens stack, the total flux of real-world light may be less than 30%. Additionally, in some embodiments, scattering from the lenses in the GP lens stack can reduce optical performance below desired levels. Additionally, the attenuation properties of the display system 1100 may cause nearby people to at least partially lose sight of the wearer's eyes, thereby making eye contact more difficult, as may be the case with a person wearing sunglasses. Display system 1100 may also cause other artifacts caused by leakage of undiffracted light, and may involve the use of switchable waveplates to change the relative power across 2 to 4 available depth planes. In some embodiments, the display system 1100 may include two waveguides instead of a single waveguide 1003 . For example, a first of the two waveguides may be configured to couple into one or two differently colored optical flows (eg, a red image flow, or a red and green image flow) that include image information, and the The second waveguide may be configured to couple into one or two additional optical streams of different colors (eg, blue and green image streams, or blue image streams, respectively) that include image information. In some embodiments in which the first waveguide includes two optical fluxes of different colors, a second waveguide of the two waveguides can be configured to couple into a different color optical flux than the first waveguide and a different color optical flux from the first waveguide. An optical stream of the same or similar color (eg, green and blue image streams, or red and blue image streams) included in a waveguide.

Figure 12 shows another embodiment of a display system 1200 that includes an imaging system 1201 and a waveguide including a high refractive index material. The various components of imaging system 1201 may be similar to corresponding components of imaging system 1001 . However, projection optics 1209 is configured to have two output pupils, each configured to emit three colors, eg, first, second, and third colors (eg, red, green, and blue) . The first output projector exit pupil is configured to emit first, second, third (eg, red, green and blue) optical flows comprising image information for the first depth or focal plane, the second projection The instrument exit pupil is configured to emit first, second, and third (eg, red, green, and blue) optical flows that include image information for a second depth plane or focal plane. First, second, and third (eg, red, green, and blue) optical fluxes emitted from the first output pupil that include image information for the first depth or focal plane are coupled into the first optical flow of the waveguide assembly 1203 inside a waveguide 1203a. The first, second, and third (eg, red, green, and blue) optical fluxes emitted from the second output pupil including image information for the second depth or focal plane are coupled into the first inside the second waveguide 1203b. Thus, embodiments of display system 1200 are configured as two depth plane systems in which the two depth plane systems are paired by separate waveguides (waveguides with light such as refractive lenses or optical elements disposed on the surface of the waveguides The power components are paired to give the optical power associated with the depth planes to address each depth plane. In some embodiments, the waveguides 1203a and 1203b may be identical to each other. Similar to waveguide 1003, waveguides 1203a and 1203b may comprise a material having a high index of refraction (eg, an index of refraction greater than about 1.79, such as about 2.3). For example, in some embodiments, the waveguides 1203a and 1203b may comprise lithium niobate or silicon carbide. Similar to waveguide 1003, waveguides 1203a and 1203b may be infinity focused. Variability in the focal position of the light emitted from the waveguides 1203a and 1203b may be provided by static refractive lenses 1205a, 1205b and 1205c (eg, thin refractive lenses), eg, similar to those commonly used in eyeglasses. Static refractive lens 1205b is located between first waveguide 1203a and the wearer's eye 1207, static refractive lens 1205c is located between first waveguide 1203a and second waveguide 1203b, and static refractive lens 1205a is located between the outside world and the second waveguide 1203b. In some embodiments, the gap between the first waveguide 1203a and the second waveguide 1203b can be large enough to accommodate the static refractive lens 1205c, but small enough to reduce the overall dimensions of the eyepiece including the waveguides 1203a and 1203b , and provides flexibility in working distance configuration and tolerances. For example, in some embodiments, the gap between the first waveguide 1203a and the second waveguide 1203b may be between about 1.0 mm to about 1.5 mm.

The refractive lenses 1205b and 1205c may be configured as negative power lenses, and the refractive lens 1205a may be configured as a positive power lens. In the embodiment of display system 1200 shown in FIG. 12, refractive lens 1205b is a plano-concave lens with a power of -0.5 diopters; refractive lens 1205c is a plano-concave lens with a power of -1.5 diopters; and The sexual lens 1205a is a plano-convex lens with an optical power of +2.0 diopters. In some embodiments, static refractive lenses can be molded. In some embodiments, static refractive lenses may be formed by other fabrication techniques. In some embodiments, static refractive lenses can be mass produced from polymers (eg, high refractive index polymers). In various embodiments, an antireflection layer may be disposed over a static refractive lens comprising a polymer. For example, in some embodiments, an inexpensive method can be used to coat a static refractive lens comprising a polymer with an antireflection layer/coating to refract the lens. Light from the first waveguide 1203a propagates through a single negative refractive index lens 1205b and is focused at a distance according to the optical power of the single negative refractive index lens 1205b. The light from the second waveguide 1203b propagates the two negative refractive lenses 1205b and 1205c and is focused at a distance according to the combined power of the two negative refractive lenses 1205b and 1205c. The outer positive refractive lens 1205a cancels the combination of the two negative refractive lenses 1205b and 1205c, resulting in a real world view unaffected by the lenses 1205b and 1205c.

The embodiment of the display system 1200 shown in FIG. 12 can utilize a multi-pupil microdisplay so that each layer can be addressed independently (thus, each depth plane or depth can have unique image content). As mentioned above, in an example, the imaging system 1201 includes two RGB mixed output pupils that output image content for two depth planes. It should be appreciated that, in various embodiments, the imaging system 1201 may be configured with geometric offset and separate R, G, and B sub-pupils or at least partially combined RGB sub-pupils (where the same coupling optics are used) input at least two colors into the same waveguide), output the red (R), green (G) and blue (B) components of the image for a particular depth plane. As discussed above, a reduction in the number of output sub-pupils in an imaging system can generally result in significantly smaller projection optics, and correspondingly smaller imaging systems, which can be advantageous for wearable systems. In various embodiments of display system 1200, imaging system 1201 may include two independent single pupil microdisplays. Stand-alone single-pupil microdisplays can be either LCOS-based single-pupil systems or stand-alone MEMs scanning projectors. In such an embodiment, each individual single pupil microdisplay is configured to direct image light to a corresponding waveguide.

In some embodiments, display system 1200 may include two waveguide assemblies for each depth plane, rather than one waveguide per depth plane. For each depth plane, the first of the two waveguides can be configured to couple into one or two different colored optical flows (eg, red image flow, or red and green) that include image information for that depth plane image flow), the second of the two waveguides may be configured to include an additional one or two optical flows of different colors for image information for that depth plane (eg, blue and green image flows, respectively, or blue image stream). In some embodiments in which the first waveguide includes two optical fluxes of different colors, a second waveguide of the two waveguides can be configured to couple into a different color optical flux than the first waveguide and a different color optical flux from the first waveguide. An optical stream of the same or similar color (eg, green and blue image streams, or red and blue image streams) included in a waveguide.

FIG. 13 shows an embodiment of an imaging system 1300 configured to provide optical flows of multiple colors including image information to a stack 1303 including disposed on glasses, such as a head mounted display, for One or more waveguides positioned in front of the wearer's eyes. In some embodiments, one or more of the waveguides may comprise a high index of refraction (eg, index of refraction greater than about 1.79) material. In various embodiments, stack 1303 may include one or more waveguides (eg, waveguides including high refractive index materials) for each depth plane. For example, for each depth plane, stack 1303 may include one waveguide that includes a high index of refraction material. The two waveguides may be configured to couple in image light having one or more different wavelengths output from imaging system 1300 such that the coupled image light propagates within the waveguides by total internal reflection. The one or more waveguides comprising the high refractive index material can be further configured to project the coupled-in to the viewer over a wide field of view (eg, a horizontal field of view greater than about 20 degrees and a vertical field of view greater than about 20 degrees). Light.

The imaging system is configured as a front-illuminated imaging system in which polychromatic unmodulated illumination light is input into the imaging system through projection optics 1307 towards modulating element 1305 via one or more input pupils. Modulating element 1305 is reflective and front-illuminated by illumination light from projection optics 1307 . Modulated light including image information is reflected from modulating element 1305 and transmitted through one or more output pupils through projection optics 1307 back toward waveguide stack 1303 . In various embodiments, imaging system 1300 may be configured with two input pupils, each configured to provide polychromatic illumination to generate images for two different depth or focal planes. In some such embodiments, imaging system 1300 may be similarly configured with two output pupils, each output pupil configured to output polychromatic image light for two different depth or focal planes. The polychromatic image light emitted from the two output pupils for two different depth or focal planes may be directed to corresponding waveguides of stack 1303 . The imaging system shown in Figure 13 has several advantages including, but not limited to, small size and/or a possibly reduced number of pupils.

Other configurations are also possible. For example, stack 1303 may include two waveguides that include a high index of refraction material for each depth plane. For example, in one illustrative design, a first of the two waveguides may be configured to couple into a first, second, or third color, such as red, green, and blue image light, output from imaging system 1300 one or more of (eg, red image light, or red and green image light, or red and blue image light) such that the coupled image light propagates within the waveguide by total internal reflection; and The second of the two waveguides may be configured to couple into one or more of the first, second, or third colors, such as red, green, and blue image light output from the imaging system 1300 (eg, , blue image light, or blue and green image light, or blue and red image light), so that the coupled-in image light propagates within the waveguide by total internal reflection.

As mentioned above, the design of projection optics (eg, projection optics 1107, 1207, and 1307) can be challenging, especially when multiple waveguides or waveguide assemblies are required to output light from the projection optics. One difficulty encountered in designing such projection optics is the limited working distance (eg, the distance from the last optical surface of the projection optics to the surface of the associated waveguide). As noted above, one advantage of employing waveguides comprising high refractive index (eg, refractive index greater than about 1.79) materials is that the number of waveguides for each depth plane or focal plane is reduced (eg, it is possible to change the number of waveguides from each Three waveguides in the depth plane are reduced to one or two waveguides per depth plane). The reduction in the number of waveguides through the use of high index materials can provide additional working distance gain, which can allow the use of projection lens design options that are not feasible in systems or eyepieces with a large number of waveguides. This additional working distance gain, as well as an embodiment of a display system configured for optimal working distance for its components, is further described below with reference to Figures 14A through 14E-3.

Figure 14A shows a display system (eg, an eyepiece of a head mounted system) with a first 1401 and a second 1403 waveguide set for two depth planes. Each waveguide set 1401, 1403 has three waveguides configured to receive multiple light beams from projection optics across a wide angular range and couple the light into the waveguides for propagation by total internal reflection. For example, the plurality of light beams may be of first, second and third colors (such as red, blue and green light including image information for the depth plane) across a range of angles associated with the field of view of the display system .

Each waveguide in FIG. 14A can be considered to have a corresponding working distance (the distance from the last optical surface of projection optics 1405 to that waveguide surface near the sub-pupil, which waveguide surface may be closer to projection optics 1405 ). near or far from the waveguide surface). As shown in Figure 14A, the sub-pupils for multiple beams are larger at the left-most and right-most waveguides compared to the sub-pupils at waveguides closer to the middle of the waveguide stack because the beams are Projection optics are manipulated by narrowing and then widening the beam carrying image data over the field of view. Therefore, the coupling elements for those leftmost and rightmost waveguides must be correspondingly larger to capture all the light of the corresponding sub-pupils.

However, large in-coupling elements may cause image efficiency problems, such as reflection of light coupled into the waveguide at some angles by the same in-coupling element before propagating through total internal reflection begins. 14E-1 shows an example of a waveguide 1403 that includes an in-coupling element 1416a that is sized enough to reflect some of the in-coupled light out of the waveguide 1403 through the same in-coupling element 1416a. The phenomenon of out-coupling in-coupled light through the same coupling element is referred to herein as "springback". One way to reduce the risk of coupling in and out light through the same coupling element is to reduce the size of the coupling element. Figure 14E-2 shows an example of a waveguide 1403 having an in-coupling element 1416b that is smaller in size than in-coupling element 1416a. However, reducing the size of the in-coupling element only to reduce springback reduces the amount of light the in-coupling element can receive. For example, if the sub-pupil at the waveguide is larger than the in-coupling element at the same waveguide, some of the received light that is not incident on the in-coupling element will not be coupled in and will be lost.

Additionally, at each bounce during total internal reflection, some amount of imperfection in the waveguide construction introduces aberrations in the optical path, so that the more bounces per waveguide, the more degraded the image quality. This problem can be reduced by using a thicker waveguide, which induces less bounce through total internal reflection. Figure 14E-3 shows an example of a waveguide 1403c that is thicker than the waveguide 1403 of Figures 14E-1 and 14E-2. Thicker waveguides can have incoupling elements large enough to receive all incoming light while reducing the risk of coupling out incoupling light through the incoupling elements. However, increasing the thickness of any waveguide (let alone all waveguides) would cause the leftmost waveguide of waveguide assembly 1401 (FIG. 14A) to be further away from projection optics 1405, resulting in an even larger sub-pupil size and requiring even greater Larger coupling components, which will further exacerbate the aforementioned efficiency issues. Thus, as noted from Figure 14A, the working distance of the waveguide assemblies 1401 and 1403 is generally limited, since any changes to the dimensions of the waveguides (eg, the thickness of the waveguides or the distance of the waveguides from the projection optics 1405) will have an effect on the sub-lights An increase in pupil size has a negative effect.

FIG. 14B shows the case if a refractive lens 1409a is introduced between the waveguide assemblies 1401 and 1403 . By placing the refractive lens 1409a between the waveguide assemblies, the sub-pupil intersections on the waveguide assembly 1401 are even further away than in Figure 14A, which would require thinner waveguides to maintain the form factor (increase in the image by increasing bounce number of aberrations) and/or larger coupling elements to receive all angles at the new sub-pupil distance (reducing the efficiency of the waveguide). In other words, placing a refractive lens 1409a that helps to improve the viewer's depth cues results in degraded image quality due to increased working distance.

As shown in Figure 14C, by replacing the first waveguide group 1401 and the second waveguide group 1403 with waveguides comprising high refractive index materials, the number of waveguides in each group can be reduced from three waveguides per depth plane to one per depth plane waveguide. In some embodiments, the number of waveguides may be reduced from three waveguides per depth plane to two waveguides per depth plane. This configuration can reduce the working distance of either waveguide because the entire waveguide assembly is now thinner. Assuming the waveguide thickness of each waveguide is between about 300 and 400 microns, Figure 14C shows recovery or "regaining" of working distances of up to 1.2 mm due to the reduction for each waveguide by virtue of the high index of refraction waveguides of Figure 14C The number of waveguides in the depth plane. The configuration shown in Figure 14C has several additional advantages due to the improved working distance or distances. For example, a smaller coupling grating can be used to couple light into the waveguide because the working distance (eg, between the waveguide and the projector) is reduced; alternatively, because the beam size incident on the waveguide is smaller, Or the thickness of the waveguide can be increased (which may actually increase the working distance) to optimize the number of bounces through total internal reflection and reduce the number of angles susceptible to the "bounce back" problem of Figure 14E-1. Although this increase in waveguide thickness was previously undesirable due to the increased working distance of successive waveguides in the stack, since the working distance has been shortened, this increased waveguide thickness has a negligible performance impact. As another example, one or more additional depth planes may be incorporated into the system, as shown in Figure 15 below.

Figures 14D-1, 14D-2 and 14D-3 illustrate an embodiment of a display system including two waveguide pairs (waveguide and refractive lens). Figure 14D-1 shows a display system with transmissive in-coupling elements 1414 and 1416 through which light propagates before reaching the waveguide, and then again, while Figure 14D-2 shows a reflective in-coupling element 1414 -1 and the display system of 1416-1 where light enters the waveguide before interacting with the element; Figure 14D-3 shows a display system utilizing both transmissive and reflective coupling elements.

Each of Figures 14D-1, 14D-1, and 14D-3 depict projection optics with a last lens 1405 that projects multiple angles from the entire projector (not shown) beams, the multiple angles are associated with an image having a field of view. The angular range covers the angular range from beam 1412 to beam 1410. The projection optics thus create a cone of light beams that narrow first and then widen over the angular range. Although only one angular range is shown, it will be appreciated that Figures 14D-1, 14D-2, and 14D-3 may also operate on a multi-pupil projector (as shown in Figure 14C), for ease of description, Figure 14D -1, 14D-2 and 14D-3 show only a single pupil.

Waveguides 1401 and 1403 intersect the sub-pupil cones at different locations. Waveguide 1401 is located where the taper widens, and waveguide 1403 is located where the taper narrows. In some embodiments, refractive lenses are placed between waveguides 1401 and 1403 .

In-coupling elements (eg, diffractive gratings) are located on waveguides 1401 and 1403 where the major surfaces intersect the sub-pupils. In Figure 14D-1, which depicts the transmissive coupling-in element, the coupling-in element is located on the surface of the waveguide that is closer to the last lens 1405 of the projection optics. In Figure 14D-2, which depicts the reflective in-coupling element, the in-coupling element is located on the surface of the waveguide farther from the last lens 1405 of the projection optics. It will be appreciated that the dimensions of the in-coupling elements may depend on which surface the in-coupling elements are disposed on, and on which waveguides the in-coupling elements are disposed. As shown in Figure 14D-1, the coupling element 1414 is smaller than the coupling element 1416; for Figure 14D-2, the situation is reversed. Increasing or decreasing the waveguide working distance 1410 or 1412 can adjust the size of the coupling element required to capture a series of beams. 14D-3 illustrates an embodiment of placing the in-coupling elements proximally or distally to increase or optimize the size of the in-coupling elements of the respective waveguide. In other words, the surface positions of the coupling elements of Figures 14D-1 and 14D-2 are not mutually exclusive and can be interchanged.

Waveguide display systems in the prior art can place the waveguides as close to the projector as possible to minimize form factor and maximize overall efficiency by minimizing in-coupling size. By implementing the high index waveguides described herein, optimization of working distance can alternatively be correlated with ideal coupling element dimensions, and then further optimization of the thickness of the waveguide and the presence of beneficial intermediate optics such as refractive or zoom lenses .

Figure 14D-1 shows the first waveguide 1403 with the coupling element 1416 on the near surface of the waveguide at a first working distance 1412 measured from the coupling element 1414 to the last lens 1405 of the projection optical system. A second waveguide 1401 with an in-coupling element 1414 located on the near plane of the waveguide is placed at a second working distance 1410 measured from the in-coupling element 1414 to the last lens 1405 of the projection optics. Figures 14D-2 and 14D-3 show similar embodiments, but with a change in the surface position of the coupling element and a corresponding change in the working distance; notably, Figure 14D-3 can use the first working distance 1412- 1 and the second working distance 1410, and it is not necessary to use a unique working distance for the particular variable configuration of its coupling into the surface arrangement of the element.

In some embodiments, at least one refractive lens 1420 is disposed between the waveguides 1401 and 1403, the at least one refractive lens 1420 being configured to provide depth cues to light propagating therethrough. In some embodiments, refractive lens 1420 has an optical prescription or optical power. It will be appreciated that in some embodiments, the thicker the lens 1420 may be, the greater the optical power it may impart, and that an increase in the thickness of the lens 1420 will also increase at least the second working distance.

In some embodiments, waveguides 1401 and 1403 (or at least their respective coupling elements 1414 or 1414-1 and 1416 or 1416-1) are placed on either side of sub-pupil transition point 1418, which contains the field of view image The angular range of the multiple beams of data transitions from a narrow cone to a wide cone. In some embodiments, the waveguides (or at least their corresponding coupling-in elements) are placed on the common side of the sub-pupil transition point 1418 . Although FIGS. 14D-1 , 14D-2 and 14D-3 illustrate the former, one of ordinary skill in the art will understand the application of the latter through the description provided herein. It should also be noted that the sub-pupil transition point 1418 or working distance as applied herein is not necessarily co-located at the pupil of the projector.

Benefits of the various systems, architectures, and designs discussed herein (eg, the embodiments shown in Figures 10, 12, 13, 14C, 14D-1, and 14D-2) include, but are not limited to: ratio, high transparency, relatively small external dimensions and thickness (eg, eyepieces have a nominal thickness of less than about 5 mm), low manufacturing cost, and low weight. A panchromatic eyepiece that includes a single waveguide with a high refractive index material (eg, refractive index greater than 1.79 and/or refractive index greater than 2.2) due to combining the three waveguides into one, compared to a panchromatic eyepiece that includes three glass waveguides The weight can be reduced.

As described above, employing waveguides comprising high index materials (eg, index greater than 1.79 and/or index greater than 2.2) can reduce the number of waveguides per depth plane, which allows the inclusion of one or more additional depth planes. FIG. 15 shows an embodiment of a display system 1500 that includes an eyepiece that includes a stack 1518 having a plurality of waveguides 1520 , 1522 and 1524 . Each waveguide 1520, 1522, and 1524 may be associated with a corresponding depth plane. (In some other embodiments, two waveguides may be associated with each depth). In some embodiments, the gap between the waveguides is about 0.3 mm. In some cases, the waveguide may include a substrate of about 400 microns. Light containing image information for each depth plane may be emitted from one or more output pupils of imaging system 1501 . For example, in the embodiment shown in Figure 15, imaging system 1501 may include three output pupils, each output pupil configured to output polychromatic image light for a corresponding depth plane. (For a similar system for providing depth or depth planes as opposed to three output pupils, two output pupils can be used). In various embodiments, the waveguides in stack 1518 may be infinity focused and may include fixed distance multifocal elements. In particular, in some such embodiments, stack 1518 may include a plurality of negative static geometric phase 1530 ("GP") lenses (eg, liquid crystal polarization gratings) positioned between the depth plane and the wearer's eyes 1507 to change The focal positions of virtual images projected from waveguides associated with different depth planes. The stack 1518 may further include a positive GP lens 1526 positioned between the outside world and the wearer's eye 1507 to compensate for the optical power introduced by the negative GP lens. Using a static GP lens can reduce the thickness and weight of stack 1518 compared to using other types of variable focus lenses. Many embodiments of GP lenses may be polarization sensitive. Accordingly, stack 1518 may further include a polarizer 1528 (eg, a circular polarizer or a polarizer-based variable attenuator including, for example, one or more liquid crystal layers and polarizers) to ensure that display system 1500 operates correctly. One disadvantage of including polarizers in stack 1518 is reduced light flux or brightness. For example, in some embodiments, including a polarizer in stack 1518 can reduce light flux by about 50%. In some embodiments, a combination of liquid crystal-based variable attenuators and polarizers may be integrated in stack 1518 .

The present application contemplates variations and combinations of the above-described display systems, including hybrid combinations of refractive and diffractive (GP) lenses and imaging systems.

In various embodiments of a front-illuminated imaging system, for example, the imaging system 1300 shown in Figure 13, an illumination pipe, or a light pipe may be used to provide illumination light to the modulation element 1305 of the imaging system. FIG. 16 shows an embodiment of a display system 1600 that includes a lighting tube 1630 . Display system 1600 includes a stack 1603 with one or more waveguides, which can be integrated into glasses or a head mounted display. Illumination tubes 1630 may be disposed between the waveguides in stack 1603. The spacing of the waveguides, affected by the thickness of one or more lens elements between the waveguides in some designs, may be 1 to 1.2 mm wide. Light from the imaging system including modulation element 1605 and projection optics 1607 is directed towards stack 1603 and coupled into the waveguide using coupling optics as described herein. Display system 1600 also includes one or more monochromatic or polychromatic individual light sources (eg, lasers or LEDs) 1632a-1632c. In the embodiment shown, the individual light sources 1632a-1632c include light sources of first, second, and third colors, such as red, green, and blue light. The light from the individual light sources 1632a-1632c is combined with a dichroic beam splitter 1634 to produce a white beam, which is injected into the illumination tube 1630. In some embodiments, a white light source (eg, a white LED) may be used to direct the white light down to the lighting tube 1630 . In such an embodiment, the beam of the combined dichroic beam splitter 1634 may be eliminated. Incident white light beams may be redirected with light redirectors or turning elements 1636 (eg, wedges and/or color mirrors) to exit illumination tube 1630 . In some embodiments, the light is redirected in a nominally orthogonal direction relative to the major surfaces of the waveguides of the illumination tube 1630 and/or stack 1603, and through the one or more waveguides of the stack 1603, via the projection optics 1607 leads towards modulation element 1605. The light is reflected from the modulating element 1605, and the modulated optical flow then propagates back through the projection optics 1607 and couples into the waveguides in the stack 1603. In some embodiments, the redirected light may be modified or modulated using conditioning optics 1638 including a diverging lens or diffractive optical element designed to modulate after propagating through projection optics 1607 The desired light distribution is produced on element 1605. In some embodiments, conditioning optics 1638 may comprise top-hat beam profile diffractive optical elements. In some cases, the adjustment optics 1638 can effectively tailor the light distribution to any design according to the needs of the display system 1600. Conditioning optics 1638 may be provided on one or both major surfaces of the waveguide. In some embodiments, conditioning optics including diffractive optical elements may be fabricated concurrently with the in-coupling and out-coupling optical elements fabricated on the surface of the waveguide. Another advantage of using a light pipe illuminator configuration is that it moves the light source away from the waveguide, which is often sensitive to thermal fluctuations or high temperatures.

In some embodiments, separate lighting tubes may be used to provide illumination light of different colors. 17A and 17B illustrate side and top views of individual illumination tubes 1730a, 1730b, and 1730c configured to provide individual colored illumination to an imaging system. In contrast to the design shown in Figure 16, in the embodiment shown in Figures 17A and 17B, no dichroic beam splitter 1634 is used, and light is coupled into the light pipe 1630 from the end of the light pipe. In the embodiment shown, light pipe 1730a is configured to provide a first color (eg, red) illumination, light pipe 1730b is configured to provide a first color (eg, green) illumination, and light pipe 1730c is configured to provide a first color (eg, green) illumination A third color (eg, blue) is illuminated. Light pipes for any color combination can be used. In such embodiments, separate diffractive optical elements (DOEs) designed or optimized for each color may be used to condition the illumination light prior to modulation. In addition, the coupling grating that receives the image light from the imaging system can also be designed or optimized, for example, for each individual color, in order to improve coupling efficiency. In various embodiments, the waveguides may be tapered to allow for closer separation.

One waveguide per depth plane

Various embodiments of the display devices described above include, for each depth plane, a single waveguide that includes a high index of refraction material (eg, an index of refraction greater than or equal to about 1.79). A multiplexed optical flow including a first color, a second color, and a third color containing image information for a depth plane is coupled into a waveguide for the depth plane using at least one in-coupling optical element. Without loss of generality, the first color, the second color and the third color may be selected from the group consisting of red, green and blue. In some embodiments, a single in-coupling optical element may be configured to redirect (eg, diffract) light of the first, second, and third colors containing image information of the depth plane into the waveguide. In other embodiments, the two in-coupling optical elements may be configured to redirect (eg, diffract) light of the first, second, and third colors containing image information of the depth plane into the waveguide through which Two in-coupling optics couple different colors or color combinations into the waveguide. For example, in some embodiments, a first of the two in-coupling optical elements may be configured to redirect (eg, diffract) light of a first color and a second color, respectively, and the two in-coupling optical elements A second of the in-coupling optical elements may be configured to redirect (eg, diffract) light of the third color. In other embodiments, a first of the two in-coupling optical elements may be configured to redirect (eg, diffract) light of a first color and a second color, and a first of the two in-coupling optical elements The second in-coupling optical element may be configured to redirect (eg, diffract) light of the third color and light of one of the first color or the second color. In some embodiments, three in-coupling optical elements (first, second, and third in-coupling optical elements) may be configured to include a first color, a second color, and a third color, respectively, of the image information of the depth plane The light is redirected (eg, diffracted) into the waveguide. For example, in some embodiments, a first of the three in-coupling optical elements may be configured to redirect (eg, diffract) light of a first color and a second of the three in-coupling optical elements, respectively, may be configured to redirect (eg, diffract) light of a first color. The optical element may be configured to redirect (eg, diffract) light of the second color, and a third of the three in-coupling optical elements may be configured to redirect (eg, diffract) light of the third color .

Two waveguides per depth plane

Various embodiments of the display devices described above may include, for each depth plane, two waveguides that include a high index of refraction material (eg, an index of refraction greater than or equal to about 1.79). A multiplexed optical flow including a first color, a second color, and a third color, containing image information of the depth plane, is coupled into two waveguides, and the first and second different colors or color combinations are coupled into the two waveguides . Without loss of generality, the first color, the second color and the third color may be selected from the group consisting of red, green and blue. In some embodiments, the first waveguide may be configured to receive and direct therein a first color and a second color, respectively, containing image information of the depth plane, and the second waveguide may be configured to receive and direct therein a first color containing the depth plane, respectively. The third color of the image information for the depth plane. In other embodiments, the first waveguide may be configured to receive and guide therein a first color and a second color, respectively, containing image information of the depth plane, and the second waveguide may be configured to receive and guide therein a first color containing the depth plane, respectively. The third color and one of the first color or the second color of the image information of the depth plane. For example, a first waveguide may receive and guide red and green therein, and a second waveguide may receive and guide green and blue or red and blue therein, respectively.

In various embodiments, at least two in-coupling optical elements are used to couple a multiplexed optical flow comprising light of a first color, a second color and a third color containing image information of the depth plane into the two waveguides. In some embodiments, the first in-coupling optical element may be configured to redirect (eg, diffract) light of the first and second colors containing image information of the depth plane into the first waveguide, respectively, and The second in-coupling optical element may be configured to redirect (eg, diffract) light of the third color containing the image information of the depth plane into the second waveguide. In some embodiments, the second in-coupling optical element may be further configured to redirect (eg, diffract) light of the first color or the second color into the second waveguide. In some embodiments, the first in-coupling optical element can be configured to redirect (eg, diffract) light of the first color containing image information of the depth plane into the first waveguide; and the second in-coupling optical element can is configured to redirect (eg, diffract) light of the second color containing image information of the depth plane into the first waveguide. The third in-coupling optical element may be configured to redirect (eg, diffract) light of a third color containing image information of a depth plane into the second waveguide of the depth plane. In some embodiments, the second in-coupling optical element may be further configured to redirect (eg, diffract) light of the first color or the second color into the second waveguide. In some other embodiments, the fourth in-coupling optical element may be configured to redirect (eg, diffract) light of the first color or the second color into the second waveguide.

Method for fabricating gratings on high index waveguides

Various embodiments of display devices including waveguides contemplated herein that include high refractive index materials (eg, refractive index greater than or equal to about 1.79) may include diffractive structures disposed on surfaces of the waveguides. As described above, a waveguide comprising a high refractive index material (eg, a refractive index greater than or equal to about 1.79) having a diffractive structure can be configured to couple emission from an imaging system (eg, a microdisplay or projector) to a beam containing image information Polychromatic light, distributing in-coupled light along one or more desired directions and/or out-coupling light toward the viewer. Different methods of fabricating waveguides comprising high refractive index materials (eg, refractive index greater than or equal to about 1.79) with diffractive features are described below.

18A and 18B illustrate flow diagrams of two different methods of fabricating diffraction gratings on the surface of a substrate (eg, a waveguide) comprising a high refractive index material (eg, a refractive index greater than 1.79). In some embodiments, the substrate may include lithium niobate (LiNbO ₃ ) or silicon carbide (SiC). As shown in block 1801, the method includes providing a high index of refraction substrate. As represented by block 1803, the method further includes disposing a layer of patternable material on the surface of the substrate. In some embodiments, the patternable material may include a layer of resist. In some embodiments, the patternable material may comprise a polymer. For example, the patternable layer may include an ultraviolet (UV) curable polymer. The index of refraction of the patternable layer may be less than the index of refraction of the substrate material (eg, the index of refraction is less than 1.79). For example, the index of refraction of the patternable layer may be between about 1.2 and about 1.8. In various embodiments, the index of refraction of the patternable layer may be greater than or equal to about 1.2 and less than or equal to about 1.3, greater than or equal to about 1.3 and less than or equal to about 1.4, greater than or equal to about 1.4 and less than or equal to about 1.5 , greater than or equal to about 1.5 and less than or equal to about 1.6, greater than or equal to about 1.6 and less than or equal to about 1.7, greater than or equal to about 1.7 and less than or equal to about 1.79, or any range/subrange between these values. In various embodiments, the thickness of the patternable layer may be between about 10 nm and about 1000 nm.

The patternable layer may be disposed over the surface of the substrate using sputter deposition techniques (eg, ink jet deposition). As noted above, certain high refractive index materials, such as lithium niobate (LiNbO3 ₎ , can be piezoelectric, ferroelectric, and/or pyroelectric, and can generate substantial surface charges in preparation for deposition of patternable materials. It may be impractical to use sputter deposition techniques to place the patternable material over the charged surface of the substrate. Thus, in some embodiments, the charged surface of the substrate comprising the high refractive index material may be discharged prior to disposing the patternable material using sputter deposition techniques.

As represented by block 1805, the patternable layer may be patterned with a desired (eg, grating or diffractive optical element) pattern. As shown in block 1807, the patterned layer may be used as an etch mask to etch the surface of a substrate comprising a high refractive index (eg, refractive index greater than or equal to about 1.79) material to create diffractive structures on the surface of the substrate.

In some embodiments, a patterned layer may be retained on the surface of a substrate that includes a high index of refraction material (eg, an index of refraction greater than or equal to about 1.79). In such embodiments, the patterned back layer may be configured to function as a diffractive optical element. Thus, the patterned layer can be configured as a functional layer.

Various exemplary embodiments of the invention are described herein. Reference is made to these examples in a non-limiting sense. They are provided to illustrate more broadly applicable aspects of the invention. Various changes may be made in the invention described, and equivalents may be substituted, without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, one or more processing actions or one or more steps, to conform to one or more objects, spirit or scope of the invention. Furthermore, as will be understood by those skilled in the art, each individual variation described and illustrated herein has discrete components and features that may be readily separated or combined with features of any of the other several without departing from the scope or spirit of the present invention. All such modifications are intended to fall within the scope of the claims associated with this disclosure.

The present invention includes methods that may be performed using the subject apparatus. The method may include the act of providing such suitable equipment. Such provision may be performed by the end user. In other words, the "provide" action merely requires the end user to acquire, access, access, locate, set up, activate, power up, or otherwise act to provide the necessary equipment in the subject method. The methods described herein can be performed in any logically possible order of the events and can be performed in the order of events described.

Exemplary aspects of the invention and details regarding material selection and fabrication have been set forth above. As for other details of the invention, they can be understood in conjunction with the patents and publications cited above and in a manner commonly known or understood by those skilled in the art. The same holds true for the method-based aspects of the invention in terms of additional actions that are typically or logically employed. Additionally, although the invention has been described with reference to several examples that optionally incorporate various features, the invention is not limited to those described or indicated with respect to each variation of the invention. Various changes may be made in the invention described, and equivalents, whether cited herein or not included for brevity, may be substituted without departing from the true spirit and scope of the invention. Also, where a series of values is provided, it is understood that every intervening value between the upper and lower limit of the range, as well as any other stated or intervening value in that range, is encompassed within the invention.

Furthermore, it is contemplated that any optional features of the described variants of the invention may be set forth and claimed independently or in combination with any one or more of the features described herein. References to singular items include the possibility that there are multiple identical items. More specifically, as used herein and in the claims associated therewith, the singular forms "a," "an," "said," and "the" include plural referents unless the specific content dictates otherwise. In other words, use of an article of manufacture permits "at least one" of the subject matter in the foregoing description and the claims associated with this disclosure. It should also be noted that such claims may be drafted to exclude any optional element. Accordingly, this statement is intended to serve as an antecedent basis for the use of exclusive terms such as "individually," "only," and the like, or the use of a "negative" limitation in connection with the recitation of claim elements.

Without the use of such an exclusive term, the term "comprising" in claims associated with the present disclosure shall allow for the inclusion of any additional element, whether or not a given number of the element is recited in such a claim, or may The addition of features is considered to alter the nature of the elements recited in these claims. Unless specifically defined herein, all technical and scientific terms used herein are to be given the broadest commonly understood meanings while maintaining claim validity.

The breadth of the present disclosure is not limited by the examples and/or subject description provided, but only by the scope of the claim language associated with this disclosure.

Various examples of devices (eg, optical devices, display devices, luminaires, integrated optical devices, etc.) and systems (eg, lighting systems) have been provided. Any of these devices and/or systems may be included in a head mounted display system to couple light (eg, through one or more in-coupling optical elements) into the waveguide and/or into the eyepiece to form an image. Additionally, the devices and/or systems may be relatively small (eg, less than 1 cm) such that one or more of the devices and/or systems may be included in a head mounted display system. For example, the device and/or system may be small relative to the eyepiece (eg, less than one-third the length and/or width of the eyepiece).

In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and variations can be made in the present invention without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings should be considered for purposes of illustration and not limitation.

Indeed, it will be appreciated that the systems and methods of the present disclosure each have several innovative aspects that are not independently responsible for or claim the desirable attributes disclosed herein. The various features and processes described above may be used independently of each other or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure.

Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may function in particular combinations as described above, even initially exemplified in this way, one or more features of an example combination may in some cases be excluded from the combination and the example combination Subcombinations or variations of subcombinations may be involved. No single feature or group of features is required or indispensable to every embodiment.

It will be understood that, unless expressly stated otherwise, or otherwise understood in the context in which it is used, expressions such as "may", "could", "may", "could", "for example" and the like used herein Conditional language is generally intended to express that certain embodiments include, while other embodiments exclude certain features, elements, and/or steps. Thus, such conditional language is generally not intended to imply that features, elements, and/or steps are in any way required for one or more embodiments, nor is it intended to imply, with or without author input or prompting, that a The embodiment or embodiments necessarily include logic for determining whether such features, elements and/or steps are included or performed in any particular embodiment. The terms "comprising", "comprising", "having" and the like are synonymous and are used inclusively in an open-ended manner and do not exclude other elements, features, acts, operations, etc. Furthermore, the term "or" is used in an inclusive sense (rather than an exclusive sense), thus, when used, for example, to concatenate lists of elements, the term "or" means one, some, or all of the list elements. In addition, the articles "a," "an," and "said" as used in this application and the appended examples should be construed to mean "one or more" or "at least one" unless stated otherwise. Similarly, although operations are shown in the figures as taking a particular order, it should be recognized that these operations need not be performed in the particular order shown, or sequential order, or that all illustrated operations be performed to achieve desirable results. Furthermore, the figures may schematically illustrate one or more example processes in flowchart form. However, other operations not shown may be incorporated into the illustratively illustrated example methods and processes. For example, one or more additional operations may be performed before, after, between, or in parallel with any of the illustrated operations. Additionally, in other embodiments, the operations may be rearranged or sequenced. In some cases, multitasking and parallel processing are advantageous. Furthermore, the separation of the various system components in the above-described embodiments should not be construed as requiring such separation in all embodiments, it being understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products. Additionally, other embodiments are within the scope of the following examples. In some cases, the actions listed in the examples can be performed in a different order and still achieve desired results.

Therefore, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the disclosure, principles and novel features disclosed herein.

Claims (106)

1. A display system comprising: an image projection device configured to emit a multiplexed optical flow including a first optical flow of a first color, a second optical flow of a second color, and a third optical flow of a third color, the first color, the The second color and the third color are different, the first optical flow, the second optical flow and the third optical flow include image content; and a waveguide comprising a material having an index of refraction greater than 1.79, the waveguide configured to receive the multiplexed optical flow emitted from the image projection device such that the first optical flow, the second optical flow and the The third optical flow is guided within the waveguide by multiple total internal reflections. 2. The display system of claim 1, wherein the waveguide comprises a material having an index of refraction greater than or equal to 2.2. 3. The display system of any one of claims 1 to 2, wherein the waveguide comprises a material with an index of refraction greater than or equal to 2.3. 4. The display system of any one of claims 1 to 3, wherein the waveguide comprises lithium niobate. 5. The display system of any one of claims 1 to 4, wherein the waveguide has a field of view greater than about 30 degrees horizontally and greater than about 24 degrees vertically. 6. The display system of claim 5, wherein the field of view of the waveguide is approximately 45 degrees in the horizontal direction and approximately 56 degrees in the vertical direction. 7. The display system of any one of claims 1 to 6, further comprising at least one variable focus optical element arranged to receive the multiplexed optical flow output from the waveguide such that the complex With at least a portion of the optical flow directed to the user's eye, the variable focus optical element is configured to vary the depth from which light from the waveguide appears to originate. 8. The display system of any one of claims 1 to 6, wherein the multiplexed optical flow comprises a first multiplexed optical flow comprising a first depth plane associated with image information. 9. The display system of claim 8, wherein the waveguide comprises a first waveguide associated with the first depth plane, wherein light emitted from the first waveguide is configured to A multiplexed optical flow is directed to the viewer to produce an image that appears to originate from the first depth plane. 10. The display system of any one of claims 8 to 9, wherein the image projection device is further configured to output a second multiplexed optical flow comprising image information associated with a second depth plane, the The second multiplexed optical flow includes a plurality of optical flows having the first color, the second color and the third color, the first color, the second color and the third color being different. 11. The display system of claim 10, further comprising: a second waveguide associated with the second depth plane, the second waveguide comprising a material having an index of refraction greater than 1.79, the second waveguide configured to receive the second multiplexed transmitted from the image projection device optical flow such that the plurality of optical flows associated with the second multiplexed optical flow are directed through the second waveguide by multiple total internal reflections. 12. The display system of claim 11, wherein the light emitted from the second waveguide is configured to direct the second multiplexed optical flow to a viewer to create an appearance that appears to originate from the first Image of the depth plane. 13. The display system of any one of claims 11 to 12, wherein the second waveguide is included in an eyepiece of a head mounted display. 14. The display system of any one of claims 9 to 13, wherein the first waveguide is included in an eyepiece of a head mounted display. 15. The display system of any one of claims 1 to 7, wherein the waveguide is included in an eyepiece of a head mounted display. 16. The display system of any one of claims 1 to 7 and 15, further comprising an in-coupling optical element configured to receive the multiplexed optical flow emitted from the image projection device and to convert the Each of the first optical flow, the second optical flow, and the third optical flow are coupled into the waveguide to be guided within the waveguide by multiple total internal reflections. 17. The display system of any of claims 1 to 16, wherein the image projection device comprises a light modulation device. 18. A display system comprising: an image projection device configured to emit a multiplexed optical flow including a first optical flow of a first color, a second optical flow of a second color, and a third optical flow of a third color, the first color, the The second color and the third color are different, the first optical flow, the second optical flow and the third optical flow include image content; and a first waveguide and a second waveguide comprising a material having an index of refraction greater than 1.79, wherein the first waveguide is configured to receive the first color and the second color, the second waveguide is configured to receive the third color, and a different color or combination of colors is coupled into the first color a waveguide and the second waveguide such that the first optical flow and the second optical flow are guided within the first waveguide by multiple total internal reflections and the third optical flow is excessive Subtotal internal reflection is guided within the second waveguide. 19. The display system of claim 18, wherein the second waveguide is further configured to receive the first color such that the first optical flow is reflected in the second waveguide through multiple total internal reflections guided within. 20. The display system of claim 18, wherein the second waveguide is further configured to receive the second color such that the second optical flow is reflected in the second waveguide through multiple total internal reflections guided within. 21. The display system of claim 18, wherein the second waveguide is configured not to couple into the first color or the second color such that the third optical flow passes through multiple times Reflections are mainly guided within the second waveguide. 22. The display system of any one of claims 18 to 21, further comprising a first in-coupling optical element in the first waveguide, the first in-coupling optical element being configured to couple the first in-coupling optical element Both an optical flow and the second optical flow are coupled into the first waveguide such that the first optical flow and the second optical flow are captured within the first waveguide by multiple total internal reflections guide. 23. The display system of any one of claims 18 to 21, further comprising a first in-coupling optical element and a second in-coupling optical element in the first waveguide, the first in-coupling optical element and the second coupling optical element are configured to couple both the first optical flow and the second optical flow, respectively, into the first waveguide such that the first optical flow and the first optical flow The two optical fluxes are guided within the first waveguide by multiple total internal reflections. 24. The display system of any one of claims 18 to 21, further comprising a third in-coupling optical element in the second waveguide, the third in-coupling optical element being configured to couple the first Three optical streams are coupled into the second waveguide such that the third optical stream is guided within the second waveguide by multiple total internal reflections. 25. The display system of claim 24, wherein the third coupling optical element is further configured to couple the first optical flow or the second optical flow into the second waveguide to The first optical flow or the second optical flow is caused to be guided within the second waveguide by multiple total internal reflections. 26. The display system of claim 24, further comprising a fourth in-coupling optical element configured to couple the first optical flow or the second optical flow into the within the second waveguide such that the first optical flow or the second optical flow is guided within the second waveguide by multiple total internal reflections. 27. A method of making a diffractive optical element, the method comprising: providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light; disposing a patternable layer over the surface of the substrate; patterning the patternable layer, the pattern including a plurality of features; and The surface of the substrate is etched through the patternable layer to fabricate structures on the surface of the substrate, wherein the structures include diffractive features configured to diffract visible light. 28. The method of claim ₂₇ , wherein the transparent material comprises LiNbO3. 29. The method of claim 27 or 28, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on all of the substrate above the surface. 30. The method of any one of claims 27 to 29, wherein the surface of the substrate is discharged prior to disposing the patternable layer. 31. The method of any one of claims 27 to 30, wherein the patternable layer comprises a resist or a polymer. 32. A method of manufacturing a diffractive optical element, the method comprising: providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light; disposing a patternable layer over the surface of the substrate; and patterning the patternable layer, the pattern including a plurality of features, wherein the plurality of features of the patterned patternable layer are configured to diffract visible light into the substrate to be directed in the substrate, or to be directed in the substrate Visible light diffracts out of the substrate. 33. The method _of claim 32, wherein the transparent material comprises LiNbO3. 34. The method of claim 32 or 33, wherein disposing the patternable layer over the surface of the substrate comprises sputter depositing the patternable layer on all of the substrate above the surface. 35. The method of any one of claims 32 to 34, wherein the surface of the substrate is discharged prior to disposing the patternable layer. 36. The method of any one of claims 32 to 35, wherein the patternable layer comprises a resist or a polymer. 37. A method of making a diffractive optical element, the method comprising: providing a substrate comprising a material with a refractive index greater than 1.79 that is transparent to visible light; sputter-depositing a patternable layer over the surface of the substrate; and The patternable layer is patterned, the pattern including a plurality of features. 38. The method of claim 37, wherein the transparent material comprises LiNbO3. 39. The method of claim 37 or 38, wherein the surface of the substrate is discharged prior to disposing the patternable layer. 40. The method of any one of claims 37 to 39, wherein the patternable layer comprises a resist or a polymer. 41. A waveguide for propagating image content by total internal reflection, the waveguide comprising: a substrate comprising a material with an index of refraction greater than 1.79 that is transparent to visible light, the substrate capable of propagating image content therein by total internal reflection; a layer over the surface of the substrate, the layer comprising a material having a lower refractive index than the substrate, the layer comprising a pattern having a plurality of features, wherein the plurality of features of the patterned patternable layer are configured to diffract visible light into the substrate to be directed therein, or to diffract visible light directed within the substrate out of the substrate the substrate. 42. The waveguide _of claim 41, wherein the transparent material comprises LiNbO3. 43. The waveguide of claim 41 or 42, wherein the surface of the substrate is discharged prior to disposing the patternable layer. 44. The waveguide of any of claims 41 to 43, wherein the patternable layer comprises a resist. 45. The waveguide of any of claims 41 to 44, wherein the patternable layer comprises a polymer. 46. A head mounted display device comprising: An eyepiece comprising at least one waveguide comprising a material having an index of refraction greater than 1.79, the waveguide comprising a first major surface, a second major surface opposite the first major surface, and a plurality of edges between the major surface and the second major surface; and A plurality of diffractive features formed in at least one of the first major surface or the second major surface. 47. The head mounted display device of claim 46, wherein the plurality of diffractive features are formed on the first major surface by etching at least one of the first major surface or the second major surface in at least one of a major surface or the second major surface. 48. The head mounted display device of claim 46 or 47, wherein the waveguide comprises a material having an index of refraction greater than 2.2. 49. The head mounted display device of any one of claims 46 to 48, wherein the waveguide comprises lithium niobate. 50. The head mounted display device of any one of claims 46 to 48, wherein the waveguide comprises silicon carbide. 51. The head mounted display device of any one of claims 46 to 50, wherein at least some of the plurality of diffractive features are configured to couple into incident image light such that the coupled image light Propagation through the waveguide by multiple total internal reflections at the first and second major surfaces. 52. The head mounted display device of any one of claims 46 to 52, further comprising a variable focus lens between the waveguide and a viewer, wherein the variable focus lens is configured to alter image light The image light propagates through the waveguide through multiple total internal reflections at the first and second major surfaces and is coupled out of the waveguide towards the viewer . 53. The head mounted display device of claim 52, wherein the variable focus lens comprises a negative lens. 54. The head mounted display device of any one of claims 52 to 53, wherein the variable focus lens comprises a liquid-filled lens. 55. The head mounted display device of any one of claims 52 to 53, wherein the variable focus lens comprises liquid crystal. 56. The head mounted display device of any one of claims 52, 53 or 55, wherein the variable focus lens comprises a geometric phase lens. 57. The head mounted display device of any one of claims 46 to 51, further comprising a negative lens between the waveguide and a viewer, such that the negative lens receives a pass through the first main Light propagating through the waveguide and being coupled out of the waveguide towards the viewer is caused by multiple total internal reflections at the surface and the second major surface. 58. The head mounted display device of claim 57, wherein the negative lens comprises a static lens. 59. The head mounted display device of claim 57 or 58, wherein the waveguide and the negative lens are included in a stacked waveguide assembly. 60. The head mounted display device of any one of claims 57 to 59, further comprising an additional waveguide paired with an additional negative lens. 61. The head mounted display device of any one of claims 57 to 60, further comprising a positive lens disposed between the waveguide and the real world. 62. The head mounted display device of any one of claims 46 to 61, further comprising a polarizer stacked with the waveguide. 63. The head mounted display device of any one of claims 46 to 62, wherein at least some of the plurality of diffractive features are configured to couple out towards the viewer by The image light propagating through the waveguide is caused by multiple total internal reflections at the major surface and the second major surface. 64. The head mounted display device of any one of claims 46 to 62, further comprising an imaging system configured to provide image light. 65. The head mounted display device of claim 64, wherein the imaging system is outside the field of view of a viewer viewing the waveguide. 66. The head mounted display device of any one of claims 64 to 65, wherein the imaging system comprises: Lighting system; a modulation element configured to receive unmodulated light from the lighting system; and A projection optical system configured to transmit the image light output by the modulation element. 67. The head mounted display device of claim 66, wherein the modulating element is reflective. 68. The head mounted display device of claim 67, wherein unmodulated image light from the illumination system is transmitted through the projection optical system toward the reflective modulation element from which it is transmitted reflected and transmitted back into the waveguide through the projection optics. 69. The head mounted display device of any one of claims 66 to 68, wherein the lighting system comprises: a light source configured to output visible light; a light pipe configured to receive the visible light output from the light source; and light redirecting elements, wherein the light pipe is configured to transmit light output from the light source toward the light redirecting element by multiple total internal reflections; and Wherein the light redirecting element is configured to redirect light propagating in the light pipe towards the modulating element. 70. The head mounted display device of claim 69, wherein the light source comprises a plurality of light emitting elements configured to emit light of a plurality of colors. 71. The head mounted display device of claim 70, wherein the plurality of light emitting elements comprise light emitting diodes or lasers. 72. The head mounted display device of any one of claims 70 to 71, further comprising an optical element configured to combine light emitted by the plurality of light emitting elements. 73. The head mounted display device of claim 72, wherein the optical element is a dichroic beam combiner. 74. The head mounted display device of any one of claims 69 to 73, wherein the light redirecting element is configured to be redirected at the light pipe through the waveguide towards the modulating element light propagating in. 75. The head mounted display device of any one of claims 69 to 74, wherein the waveguide further comprises light conditioning optics configured to tailor the distribution of light redirected by the light redirecting element . 76. A head mounted display device comprising: image projection equipment; and An eyepiece including a waveguide comprising silicon carbide, the waveguide including a first major surface, a second major surface opposite the first major surface, and between the first major surface and the second major surface multiple edges of Wherein the waveguide is configured to receive and direct light therein from the image projection device to direct an image into the eyes of a wearer of the head mounted display. 77. The head mounted display device of claim 76, further comprising a plurality of diffractive features disposed on at least one of the first major surface or the second major surface. 78. The head mounted display device of claim 77, wherein the plurality of diffractive features are formed on the first major surface by etching at least one of the first major surface or the second major surface in at least one of a major surface or the second major surface. 79. The head mounted display device of any one of claims 77 to 78, wherein at least some of the plurality of diffractive features are configured to couple into incident image light such that the coupled in image light Propagation through the waveguide is by multiple total internal reflections at the first and second major surfaces. 80. The head mounted display device of any one of claims 76 to 79, further comprising a variable focus lens between the waveguide and a viewer, wherein the variable focus lens is configured to alter image light The image light propagates through the waveguide through multiple total internal reflections at the first and second major surfaces and is coupled out of the waveguide towards the viewer . 81. The head mounted display device of claim 80, wherein the variable focus lens comprises a negative lens. 82. The head mounted display device of any one of claims 80 to 81, wherein the variable focus lens comprises a liquid-filled lens. 83. The head mounted display device of any one of claims 80 to 81, wherein the variable focus lens comprises liquid crystal. 84. The head mounted display device of any one of claims 80, 81 or 83, wherein the variable focus lens comprises a geometric phase lens. 85. The head mounted display device of any one of claims 76 to 79, further comprising a negative lens between the waveguide and a viewer such that the negative lens receives a pass through the first main Light propagating through the waveguide and being coupled out of the waveguide towards the viewer is caused by multiple total internal reflections at the surface and the second major surface. 86. The head mounted display device of claim 85, wherein the negative lens comprises a static lens. 87. The head mounted display device of claim 85 or 86, wherein the waveguide and the negative lens are included in a stacked waveguide assembly. 88. The head mounted display device of any one of claims 85 to 87, further comprising an additional waveguide paired with an additional negative lens. 89. The head mounted display device of any one of claims 85 to 88, further comprising a positive lens disposed between the waveguide and the real world. 90. The head mounted display device of any one of claims 76 to 89, further comprising a polarizer stacked with the waveguide. 91. The head mounted display device of any one of claims 76 to 90, wherein at least some of the plurality of diffractive features are configured to couple out towards the viewer by The image light propagating through the waveguide is caused by multiple total internal reflections at the major surface and the second major surface. 92. The head mounted display device of any one of claims 76 to 91, further comprising an imaging system configured to provide image light. 93. The head mounted display device of claim 92, wherein the imaging system is outside the field of view of a viewer viewing the waveguide. 94. The head mounted display device of any one of claims 92 to 93, wherein the imaging system comprises: Lighting system; a modulation element configured to receive unmodulated light from the lighting system; and A projection optical system configured to transmit the image light output by the modulation element. 95. The head mounted display device of claim 94, wherein the modulating element is reflective. 96. The head mounted display device of claim 95, wherein unmodulated image light from the illumination system is transmitted through the projection optical system toward the reflective modulation element from which it is transmitted reflected and transmitted back into the waveguide through the projection optics. 97. The head mounted display device of any one of claims 94 to 96, wherein the lighting system comprises: a light source configured to output visible light; a light pipe configured to receive the visible light output from the light source; and light redirecting elements, wherein the light pipe is configured to transmit light output from the light source toward the light redirecting element by multiple total internal reflections; and Wherein the light redirecting element is configured to redirect light propagating in the light pipe towards the modulating element. 98. The head mounted display device of claim 98, wherein the light source comprises a plurality of light emitting elements configured to emit light of a plurality of colors. 99. The head mounted display device of claim 98, wherein the plurality of light emitting elements comprise light emitting diodes or lasers. 100. The head mounted display device of any one of claims 98 to 99, further comprising an optical element configured to combine light emitted by the plurality of light emitting elements. 101. The head mounted display device of claim 100, wherein the optical element is a dichroic beam combiner. 102. The head mounted display device of any one of claims 98 to 101, wherein the light redirecting element is configured to be redirected at the light pipe through the waveguide towards the modulating element light propagating in. 103. The head mounted display device of any one of claims 98 to 102, wherein the waveguide further comprises light conditioning optics configured to tailor the distribution of light redirected by the light redirecting element . 104. The display system of any one of claims 1 to 26, wherein the waveguide material comprises silicon carbide. 105. The method of any one of claims 27 to 40, wherein the transparent material comprises silicon carbide. 106. The waveguide of any of claims 41 to 45, wherein the transparent material comprises silicon carbide.

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